JP2011085531A - Method and device for measuring cadmium in food - Google Patents
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Abstract
Description
この発明は、電気化学測定法で食品中のカドミウム濃度を測定する方法及び装置に関する。 The present invention relates to a method and an apparatus for measuring a cadmium concentration in food by an electrochemical measurement method.
カドミウムは土壌中、水中、大気中の自然界に広く分布していることから、ほとんどの食品中に環境由来のカドミウムが多少なりとも含まれている。過去、我が国においては、鉱山に汚染源とするカドミウム汚染地域が数多く存在し、イタイイタイ病の発生を契機に、カドミウム曝露に関する疫学調査が数多く実施された。 Because cadmium is widely distributed in the natural world in soil, water, and air, most foods contain some cadmium derived from the environment. In the past, there were many cadmium-contaminated areas in the mine as the source of pollution in the mine, and many epidemiological studies on cadmium exposure were conducted in the wake of the occurrence of itai-itai disease.
我が国の米中カドミウム濃度は、他国に比べて高い傾向にあり、図１９に示すように、トータルダイエット調査（２００５年）によれば、日本における米からのカドミウム摂取量は、食品全体の約半分を占めている。 The cadmium concentration in rice in Japan tends to be higher than in other countries. As shown in FIG. 19, according to the total diet survey (2005), cadmium intake from rice in Japan is about half of the total food. Accounted for.
食品衛生法では、１９７０年１０月に玄米のカドミウム含有量は１．０ｐｐｍ未満（精白米は０．９ｐｐｍ未満）と定められ、玄米１．０ｐｐｍ以上のカドミウム米の販売が禁止されている。また、０．４ｐｐｍ以上１．０ｐｐｍ未満の米は、政府買入れにより非食用として処理されてきた。 According to the Food Sanitation Law, the cadmium content of brown rice was determined to be less than 1.0 ppm (less than 0.9 ppm for polished rice) in October 1970, and the sale of cadmium rice with a brown rice content of 1.0 ppm or more is prohibited. Further, rice of 0.4 ppm or more and less than 1.0 ppm has been treated as non-edible by government purchase.
国際機関においては、２００６年の第２９回コーデックス委員会総会において、食品中のカドミウムの国際基準値として、精米が０．４ｍｇ／ｋｇ、海産二枚貝（カキ及びホタテガイを除く）及び頭足類（内臓を除去したもの）が２．０ｍｇ／ｋｇが最終採択された。なお、穀類、小麦、野菜等の国際基準値は既に採択済みである。 In the international organization, at the 29th Codex Committee General Meeting in 2006, as the international standard value of cadmium in foods, polished rice is 0.4 mg / kg, marine bivalve (excluding oysters and scallops) and cephalopods ( 2.0 mg / kg with the internal organs removed) was finally adopted. International standards such as cereals, wheat and vegetables have already been adopted.
このような国際的な評価を踏まえ、玄米を含めた食品における許容基準を国際基準に適合させることが求められており、２００５年、厚生労働省は「食品からのカドミウム摂取の現状に係る安全性確保について」に係る食品健康影響評価を食品安全委員会に依頼した。そして、食品安全委員会では、２００８年６月、カドミウムの許容週間摂取量を７μｇ／ｋｇ体重／週と結論した。これは、日本国内における米等の食品を経由したカドミウムの慢性的な経口曝露を受けている住民を対象とした疫学調査結果に基づき導き出されたものである。 Based on this international evaluation, it is required to meet international standards with acceptable standards for foods including brown rice. In 2005, the Ministry of Health, Labor and Welfare stated, “Ensuring the safety of cadmium intake from foods. We asked the Food Safety Commission for a food health impact assessment. In June 2008, the Food Safety Committee concluded that the acceptable weekly intake of cadmium was 7 μg / kg body weight / week. This was derived based on the results of epidemiological surveys of residents in Japan who received chronic oral exposure to cadmium via foods such as rice.
農作物等の食品中のカドミウム濃度の公定分析法は、「農用地土壌汚染対策地域の指定要件に係るカドミウム量の検定の方法を定める省令」に定められている。この省令において、米や玄米中のカドミウム含有量の検定方法は、硝酸・硫酸で試料を加熱分解後、溶媒抽出して原子吸光光度計により農作物中の重金属含有量を測定すると定められている。図２０に公定分析法に係る測定フロー図を示す。 The official analysis method for the cadmium concentration in foods such as agricultural products is stipulated in “Ministerial Ordinance for Establishing Methods for Cadmium Amount Concerning Designated Requirements for Agricultural Soil Contamination Countermeasure Areas”. This ministerial ordinance stipulates that the cadmium content in rice and brown rice is determined by heat digesting the sample with nitric acid / sulfuric acid, extracting the solvent, and measuring the heavy metal content in the crop using an atomic absorption photometer. FIG. 20 shows a measurement flow chart according to the official analysis method.
また、一般的な米や玄米中のカドミウム含有量の測定方法として、原子吸光光度計の他に、誘導結合プラズマ発光分析装置（ＩＣＰ）、同位体希釈質量分析法（表面電離法）、同位体希釈質量分析法（ＩＣＰ−ＭＳ）等の機器分析装置でも食品中のカドミウム測定が可能である。 In addition to atomic absorption spectrophotometers, inductively coupled plasma optical emission spectrometer (ICP), isotope dilution mass spectrometry (surface ionization), isotope methods for measuring cadmium content in general rice and brown rice An instrumental analyzer such as dilution mass spectrometry (ICP-MS) can also measure cadmium in food.
しかしながら、「農用地土壌汚染対策地域の指定要件に係るカドミウム量の検定の方法を定める省令」に定める測定方法は、非常に煩雑で時間を要する。そこで、同方法の前段階に実施する調査として、重金属に汚染された農耕地、農作物の絞り込み（スクリーニング）を目的とした簡易な測定法として、蛍光Ｘ線分析装置を使用した方法が提案されている（例えば、特許文献１）。 However, the measurement method set forth in “Ministerial Ordinance for Establishing a Method for Examining the Cadmium Amount Concerning Designated Requirements for Agricultural Land Soil Contamination Countermeasure Areas” is very complicated and time consuming. Therefore, as a survey to be carried out in the previous stage of the method, a method using a fluorescent X-ray analyzer has been proposed as a simple measurement method aimed at narrowing (screening) farmland contaminated with heavy metals and crops. (For example, Patent Document 1).
その他のカドミウム濃度の測定方法としては、電気化学的測定法を利用する方法（例えば、特許文献２）や、イムノクロマトグラフィー法を利用したバイオセンサーを利用する方法（例えば、特許文献３、４）、が提案されている。
Other methods for measuring the cadmium concentration include a method using an electrochemical measurement method (for example, Patent Document 2), a method using a biosensor using an immunochromatography method (for example,
電気化学測定法は、化学物質の変化を電気化学反応としてとらえ、電位、電流、電気量等を測定パラメータとして調べる方法である。 The electrochemical measurement method is a method in which a change in a chemical substance is regarded as an electrochemical reaction, and potential, current, quantity of electricity, etc. are examined as measurement parameters.
電気化学測定法の特長は簡便さであり、測定困難な化学量を測定が容易な電気量に直接変換でき、高感度の測定が可能なことである。さらに、測定機器が極めて安価であることもある。 The feature of the electrochemical measurement method is simplicity, the ability to directly convert a difficult-to-measure chemical quantity into an easy-to-measure electric quantity, and a highly sensitive measurement is possible. Furthermore, the measuring instrument can be very inexpensive.
イムノクロマトグラフィー法は、食品をミル型破砕機等で破砕した後、０．１モル／Ｌ程度の塩酸と混合し、必要に応じて遠心分離や濾過等で食品に由来する夾雑物を除去して得られた水溶液をカートリッジに通水して濃縮させる。そして、この濃縮液をカドミウムと反応する抗体と混合し、イムノクロマトグラフィーによりカドミウム濃度に応じた発色によりカドミウム濃度を測定する測定方法である。 In the immunochromatography method, food is crushed with a mill-type crusher, etc., and then mixed with about 0.1 mol / L hydrochloric acid, and if necessary, contaminants derived from the food are removed by centrifugation or filtration. The aqueous solution obtained is passed through a cartridge and concentrated. The concentrated solution is mixed with an antibody that reacts with cadmium, and the cadmium concentration is measured by color development according to the cadmium concentration by immunochromatography.
上述のように、公定分析法に用いられる原子吸光光度計等の機器分析装置は、高価で、操作が煩雑であるため、専門の技術者でないと精度良く測定できない。つまり、公定分析方法は、図２０に示すとおり、各種無機酸や有機化合物を使用するため、試料の調製操作も煩雑である。また、酸性ガスや有機溶媒等の揮散による分析技術者の健康被害も懸念される。 As described above, instrumental analyzers such as atomic absorption photometers used in official analysis methods are expensive and cumbersome to operate, and therefore cannot be measured with high accuracy unless they are professional engineers. That is, since the official analysis method uses various inorganic acids and organic compounds as shown in FIG. 20, the sample preparation operation is also complicated. There is also concern about the health hazards of analytical engineers due to volatilization of acid gases and organic solvents.
また、原子吸光光度計、誘導結合プラズマ発光分析装置、同位体希釈質量分析装置等の機器分析装置は、大型で、据置き型のため、食品の生産・流通の場で多数の検体を迅速に測定する用途には不向きである。さらに、公定分析法は測定結果が出るまでに約５日間かかり、その間、食品を倉庫等に保管しておかなくてはならないため生産の効率が悪い。 In addition, instrument analyzers such as atomic absorption spectrometers, inductively coupled plasma emission analyzers, and isotope dilution mass spectrometers are large and stationary so that a large number of specimens can be quickly collected in food production and distribution. It is not suitable for measuring applications. Furthermore, the official analysis method takes about 5 days until the measurement result is obtained, and during that time, the food must be stored in a warehouse or the like, so that the production efficiency is low.
一方、蛍光Ｘ線分析装置は、溶液の測定ができないため溶出量試験ができない、炭化前後の質量測定により濃縮率を計算する必要がある、感度が低いため濃縮しないと測定できない、危険なＸ線を使用する等の問題を有している。 On the other hand, the fluorescent X-ray analyzer cannot measure the solution because the solution cannot be measured. It is necessary to calculate the concentration rate by mass measurement before and after carbonization. Have problems such as using.
電気化学測定法において用いられる電極の種類は、作用電極、参照電極、対電極である。通常、電気化学反応の進行に伴って作用電極の汚染により電位が変化してしまう。そこで、水溶液中の重金属イオンの測定を行う場合には、参照電極に対する作用電極の電位を常に一定になるよう制御し、作用電極と対電極の間に流れる電流値の変化を測定する方式をとる。 The types of electrodes used in the electrochemical measurement method are a working electrode, a reference electrode, and a counter electrode. Normally, the potential changes due to contamination of the working electrode as the electrochemical reaction proceeds. Therefore, when measuring heavy metal ions in an aqueous solution, a method is employed in which the potential of the working electrode with respect to the reference electrode is always controlled to be constant, and the change in the current value flowing between the working electrode and the counter electrode is measured. .
通常、電極として水銀を使用する場合が多く、微量ではあるが、試料液中に水銀が溶出するため、試料水の廃棄に問題があった。 Usually, mercury is often used as an electrode, and although it is in a very small amount, mercury is eluted in the sample solution, which causes a problem in disposal of the sample water.
また、イムノクロマトグラフィー法を利用したバイオセンサーを利用する方法は、カドミウムを濃縮させる前処理が必要である、亜鉛、マンガン、銅等の金属の影響を受ける等の問題を有している。 In addition, a method using a biosensor using an immunochromatography method has problems such as requiring a pretreatment for concentrating cadmium and being affected by metals such as zinc, manganese and copper.
さらに、イムノクロマトグラフィー法では、カドミウム単体での分子量が低いので免疫動物が抗体を作製できるように蛋白質との複合体を作製する必要があるが、この蛋白質との複合体を作製する操作が煩雑で専門家でないと作製できない。そして、抗体を作製するのに２ヶ月以上の日数が必要である。また、作製した抗体が市販されているが、かなり高価であるため、測定数が多い測定には莫大な費用がかかり、簡易測定の目的の一つである現場でのスクリーニングには不向きである。 Furthermore, in the immunochromatography method, since the molecular weight of cadmium alone is low, it is necessary to prepare a complex with a protein so that an immunized animal can produce an antibody. However, the procedure for preparing the complex with this protein is complicated. Can only be made by an expert. Then, it takes two or more days to produce the antibody. In addition, although the prepared antibody is commercially available, it is quite expensive, so that a large number of measurements require enormous costs, and is not suitable for on-site screening, which is one of the purposes of simple measurement.
上記課題を鑑みて、本発明は食品中のカドミウム濃度を高精度に測定ができる簡便なカドミウム濃度測定方法、及びカドミウム濃度測定装置を提供することを目的としている。 In view of the above problems, an object of the present invention is to provide a simple cadmium concentration measuring method and a cadmium concentration measuring apparatus capable of measuring a cadmium concentration in food with high accuracy.
上記目的を達成する本発明のカドミウム測定方法は、食品中のカドミウム測定方法であって、前記食品を強熱灰化し、前記強熱灰化した食品を酸と混合し、前記混合された混合液から溶液を分離し、前記溶液を電気化学測定法に供することを特徴としている。 The cadmium measurement method of the present invention that achieves the above object is a method for measuring cadmium in food, wherein the food is ignited with high heat, the ashed food is mixed with an acid, and the mixed liquid is mixed. The solution is separated from the solution, and the solution is subjected to an electrochemical measurement method.
この電気化学測定法は、水銀電極の代わりに銅電極を使用する水銀フリーのアノーディック・ストリッピング・ボルタンメトリー法による測定法を用いている。 This electrochemical measurement method uses a mercury-free anodic stripping voltammetry method that uses a copper electrode instead of a mercury electrode.
また、上記目的を達成する本発明のカドミウム測定装置は、食品中のカドミウムを測定する装置であって、前記食品を強熱灰化する強熱灰化手段と、前記強熱灰化手段により灰化された食品と酸を混合し、前記混合された混合液から分離された溶液を収納する手段と、前記溶液に、作用電極としての銅電極と、対電極を浸漬する手段と、前記作用電極と前記対電極との間に前記溶液中のカドミウムが前記作用電極上に析出する電圧を印加する手段と、前記作用電極と前記対電極との間に前記作用電極上に析出したカドミウムが溶出する電圧を印加する手段と、前記作用電極と前記対電極との間に流れる電流を検出する手段とを備えることを特徴としている。 Further, the cadmium measuring device of the present invention that achieves the above object is a device for measuring cadmium in foods, an ashing means for ashing the food, and an ash by means of the ashing means. Means for mixing the mixed food and acid, storing the solution separated from the mixed liquid, a copper electrode as a working electrode, means for immersing a counter electrode in the solution, and the working electrode Means for applying a voltage at which cadmium in the solution is deposited on the working electrode between the working electrode and the counter electrode, and cadmium deposited on the working electrode is eluted between the working electrode and the counter electrode It is characterized by comprising means for applying a voltage and means for detecting a current flowing between the working electrode and the counter electrode.
以上の発明によれば、簡便な方法で食品中のカドミウム濃度を高精度に測定することができる。 According to the above invention, the cadmium concentration in food can be measured with high accuracy by a simple method.
本発明は、迅速に精度良く食品中のカドミウム濃度を測定する方法、及びカドミウム濃度測定装置に関するものであり、カドミウム濃度を測定する食品を、強熱灰化処理後、強熱灰化処理された食品を酸に溶解させ、その溶液を電気化学測定に供することを特徴としている。 The present invention relates to a method for quickly and accurately measuring a cadmium concentration in a food and a cadmium concentration measuring apparatus, and a food for measuring a cadmium concentration was subjected to a heat ashing treatment after a heat ashing treatment. It is characterized by dissolving food in an acid and subjecting the solution to electrochemical measurement.
玄米などの食品中において、鉄・カルシウム・マグネシウム・亜鉛・カドミウム等の不純物は、フィチン酸と結合してフィチン酸塩の形態で多く存在する。 In foods such as brown rice, many impurities such as iron, calcium, magnesium, zinc, and cadmium are present in the form of phytate in combination with phytic acid.
フィチン酸は生体物質の一種で、組成式はＣ6Ｈ18Ｏ24Ｐ6、分子量は６６０．０８、種子など多くの植物組織に存在する主要なリンの貯蔵形態であり、キレート作用が強く、多くの金属イオンと強く結合する、
したがって、食品中に上記不純物がフィチン酸と結合してフィチン酸塩の形態で存在しており、本発明における測定対象物であるカドミウムを電気化学方法で測定する場合には、フィチン酸塩の形態で存在していると想定されるカドミウムを、フィチン酸塩を分解しカドミウム単独で分離する必要がある。
Phytic acid is a kind of biological substance, the composition formula is C 6 H 18 O 24 P 6 , the molecular weight is 660.08, and is a major phosphorus storage form present in many plant tissues such as seeds, and has a strong chelating action, Binds strongly to many metal ions,
Therefore, when the impurities are present in the form of phytate in combination with phytic acid in food, and the cadmium which is the measurement object in the present invention is measured by an electrochemical method, the form of phytate It is necessary to separate cadmium, which is assumed to exist in cadmium, by decomposing phytate and separating cadmium alone.
フィチン酸は、有機物であるため、加熱により容易に分解することができる。しかし、残った不純物類は不純物同士で結合した状態となり、カドミウムは分離できない。そこで、この不純物同士の結合をほどいてカドミウムを分離する必要がある。 Since phytic acid is an organic substance, it can be easily decomposed by heating. However, the remaining impurities are bonded to each other, and cadmium cannot be separated. Therefore, it is necessary to separate the cadmium by unbonding the impurities.
そのために、強熱灰化処理する際、フィチン酸塩分解後にカドミウムと結合する可能性がある不純物中で最大融点を示す亜鉛の融点（４１９．６℃）以上に加熱下限温度を設定して、亜鉛とカドミウムが結合する前に溶融分離する必要がある。一方、加熱上限温度は、カドミウムの沸点（７５６．０℃）以下とすれば気化による損失を防げる。 For this purpose, when performing the heat ashing treatment, the lower heating limit temperature is set above the melting point (419.6 ° C.) of zinc, which shows the maximum melting point among impurities that may be combined with cadmium after phytate decomposition, It is necessary to melt and separate before the zinc and cadmium are combined. On the other hand, loss due to vaporization can be prevented if the heating upper limit temperature is not higher than the boiling point of cadmium (756.0 ° C.).
本発明において、カドミウム濃度を測定する食品は、特に限定するものではない。例えば、国立医薬品食品衛生研究所が、地方衛生研究所と協力して行っている調査では、食品分類を「米・米製品」、「穀類・芋」「豆、豆加工品」、「緑黄色野菜」、「野菜・海藻類」、「魚介類」、「その他」に大分類しているがこの分類すべての食品を対象とする。 In the present invention, the food for measuring the cadmium concentration is not particularly limited. For example, in a study conducted by the National Institute of Health Sciences in cooperation with the Regional Health Institute, the food classification is “rice / rice products”, “cereals / rice cakes”, “beans, processed beans”, “green-yellow vegetables” ”,“ Vegetables / Seaweed ”,“ Seafood ”, and“ Other ”, but all foods in this category are covered.
本発明に係るカドミウム濃度測定方法によれば、測定時間の短時間化だけを考慮するのであれば、高価で、大型の据置き型の機器分析装置（例えば、誘導結合プラズマ発光分析装置）により、公定法では約５日間かかる測定時間を約２時間に短縮できることが確認されている。 According to the cadmium concentration measuring method according to the present invention, if only the measurement time is shortened, it is expensive, and by a large-sized stationary instrumental analyzer (for example, inductively coupled plasma emission spectrometer), According to the official method, it has been confirmed that the measurement time required for about 5 days can be shortened to about 2 hours.
しかしながら、発明者らは汚染された農作物が市場に流通する危険をなくすために、高精度の測定が可能な電気化学測定法により現場でのオンサイト測定ができる簡便な測定方法を提供することを目的としている。そして、電気化学測定法で測定できる方法について鋭意研究した結果、図１に示す測定フローにより食品中のカドミウム濃度を迅速に測定できることを見いだした。 However, the inventors have provided a simple measurement method that enables on-site measurement in the field by an electrochemical measurement method capable of high-precision measurement in order to eliminate the risk of contaminated crops circulating in the market. It is aimed. And as a result of earnest research about the method which can be measured with an electrochemical measuring method, it discovered that the cadmium density | concentration in a foodstuff could be measured rapidly with the measurement flow shown in FIG.
電気化学測定法は、電極上での酸化還元反応に伴う電流変化及び電圧変化を測定する非常にシンプルな方法であるにもかかわらず、高感度測定が可能で、消耗する部分がほとんどないという利点がある。 The electrochemical measurement method is an extremely simple method for measuring current and voltage changes associated with oxidation-reduction reactions on the electrode. There is.
さらに、本発明の実施形態で例示するクーロメトリー法は、試料中の対象成分を全量検出する再現性に優れた技法であるため、国内外に汎用化が可能で、環境改善・社会経済的好循環に多大な貢献が期待される。 Furthermore, the coulometric method exemplified in the embodiment of the present invention is a technique with excellent reproducibility for detecting the total amount of the target component in the sample, and therefore can be used universally in Japan and overseas, improving the environment and socioeconomic virtuous cycle. A great contribution is expected.
本発明に係る電気化学測定装置は、試料を強熱灰化する強熱灰化手段と、試料が導入されるセル（溶液を収納する手段）、作用電極、参照電極、対電極、及び作用電極の電位を制御する手段と、作用電極と対電極の間に流れる電流を測定する手段より構成される。 The electrochemical measurement apparatus according to the present invention includes an ignition ashing means for ashing a sample, a cell (means for storing a solution) into which the sample is introduced, a working electrode, a reference electrode, a counter electrode, and a working electrode. And a means for measuring a current flowing between the working electrode and the counter electrode.
強熱灰化手段としては、試料を空気（または、酸素）気流化で加熱できるものであればよく、電気炉等が例示される。 Any ignition ashing means may be used as long as the sample can be heated by air (or oxygen) airflow, and an electric furnace or the like is exemplified.
作用電極の電位の制御手段は、既知のものを用いればよい。この電位制御手段により、電気化学反応の進行と共に作用電極が汚染され電位が変化しても、作用電極の電位が変化しないように常に参照電極に対する作用電極の電位を一定に保つことが可能となる。したがって、作用電極の電位を一定に保った状態で作用電極と対電極の間に流れる電流を測定することができる。 A known means may be used as the means for controlling the potential of the working electrode. This potential control means makes it possible to always keep the potential of the working electrode constant with respect to the reference electrode so that the potential of the working electrode does not change even if the potential changes due to contamination of the working electrode as the electrochemical reaction proceeds. . Therefore, the current flowing between the working electrode and the counter electrode can be measured with the potential of the working electrode kept constant.
上記構成を有する電気化学測定装置において、高感度に電気化学測定を行うために、作用電極、参照電極、対電極、試料を測定するためのセル、及び電解液を最適化するとよい。 In the electrochemical measurement apparatus having the above configuration, in order to perform electrochemical measurement with high sensitivity, the working electrode, the reference electrode, the counter electrode, the cell for measuring the sample, and the electrolytic solution may be optimized.
作用電極としては、銅電極の他、白金電極、金電極、炭素系電極を用いてもよい。 As the working electrode, a copper electrode, a platinum electrode, a gold electrode, or a carbon-based electrode may be used.
参照電極は、種類、安定性、使い易さを考慮して、周知の参照電極（例えば、標準水素電極等）から適当なものを選択して用いればよい。本発明では参照電極として、銀／塩化銀電極を用いた例を示す。 In consideration of the type, stability, and ease of use, a suitable reference electrode may be selected from known reference electrodes (for example, a standard hydrogen electrode). In the present invention, an example using a silver / silver chloride electrode as a reference electrode is shown.
対電極は、種類、大きさ（表面積）を最適化するとよい。対電極としては、白金電極が用いられることが多いが、対電極は、白金電極に限るものではない。 The counter electrode may be optimized in type and size (surface area). A platinum electrode is often used as the counter electrode, but the counter electrode is not limited to the platinum electrode.
また、電解液は、種類、溶存酸素の除去、濃度を最適化するとよい。例えば、試料水は一定量計量し、電解質及び緩衝液からなる専用試薬と混合し測定検液とする。セルは、測定に最適な、大きさ、形状を選択するとよい。 In addition, the type of electrolyte, removal of dissolved oxygen, and concentration should be optimized. For example, a certain amount of sample water is weighed and mixed with a dedicated reagent consisting of an electrolyte and a buffer solution to obtain a measurement test solution. The size and shape of the cell that is optimal for measurement may be selected.
本発明に係る電気化学測定装置で行う電気化学測定法としては、例えば、アノーディック・ストリッピング・ポルタンメトリー法が挙げられる。アノーディック・ストリッピング・ポルタンメトリー法は、水溶液中の重金属イオンを電極上に還元濃縮し、濃縮した重金属物質を酸化溶出する際の電流値により重金属物質濃度を算出する方法であり、測定感度が高いという利点を有している。 Examples of the electrochemical measurement method performed with the electrochemical measurement apparatus according to the present invention include the anodic stripping portammetry method. The anodic stripping portammetry method is a method of reducing and concentrating heavy metal ions in an aqueous solution on an electrode, and calculating the concentration of heavy metal substances based on the current value when the concentrated heavy metal substances are oxidized and eluted. Has the advantage of high.
図１を参照して、本発明に係るカドミウム濃度測定方法について説明する。 The cadmium concentration measuring method according to the present invention will be described with reference to FIG.
まず、ステップＳ１において、カドミウム濃度を測定する食品（以後、試料とする）を秤量し、粉砕する。粉砕手段は、試料に応じて適宜選択すればよく、穀類・種子等の粉砕にはコーヒーミル等を用いればよく、アサリ・ホタテ貝等を粉砕する場合には包丁等を用いればよい。 First, in step S1, food (hereinafter referred to as a sample) whose cadmium concentration is to be measured is weighed and pulverized. The pulverizing means may be appropriately selected depending on the sample, a coffee mill or the like may be used for pulverizing cereals and seeds, and a knife or the like may be used when pulverizing clams and scallops.
ステップＳ２では、粉砕した試料をカドミウム濃度を測定するために必要な量だけ秤量する。粉砕した試料が粉体である場合、篩にかけてもよい。篩の目の大きさは適宜選択可能である。 In step S2, the crushed sample is weighed by an amount necessary for measuring the cadmium concentration. When the pulverized sample is powder, it may be sieved. The size of the sieve mesh can be selected as appropriate.
ステップＳ３では、ステップＳ２で秤量した粉砕された試料の強熱灰化処理を行う。 In step S3, an intense ashing process is performed on the crushed sample weighed in step S2.
本発明における強熱灰化処理とは、試料を空気や酸素流下において、電気炉で６００℃程度の温度で一定時間焼いて、水分や有機物（炭水化物、たんぱく質、脂質、ビタミン等）及び塩素等の低沸点無機物を分解または除去する処理のことをいう。 The ignition ashing process in the present invention means that a sample is baked in an electric furnace at a temperature of about 600 ° C. for a certain period of time in a stream of air or oxygen, and water, organic matter (carbohydrate, protein, lipid, vitamin, etc.), chlorine, etc. This refers to a treatment that decomposes or removes low-boiling inorganic substances.
強熱灰化処理することにより、単に試料から有機物を灰化し除去することができるだけでなく、亜鉛の融点以上でカドミウムの沸点以下の温度で加熱することにより、カドミウム測定の妨げとなる不純物の結合がほどけて分離することができる。 By ashing and ashing, organic substances can not only be ashed and removed, but by heating at a temperature above the melting point of zinc and below the boiling point of cadmium, binding of impurities that interfere with cadmium measurement Can be separated.
ステップＳ４では、ステップＳ３で強熱灰化処理した試料を放冷後、酸と混合する。試料と混合する酸の種類は特に限定するものではなく、塩酸、希硫酸等、測定に用いる電極と反応しない酸を用いればよい。 In step S4, the sample subjected to the ashing treatment in step S3 is allowed to cool and then mixed with an acid. The kind of acid mixed with the sample is not particularly limited, and an acid that does not react with the electrode used for measurement, such as hydrochloric acid or dilute sulfuric acid, may be used.
ステップＳ５では、ステップＳ４で得られる混合液を振とうし、ステップＳ６で混合液を濾過する。濾過するために用いる濾紙等のフィルターの種類は、混合液の残渣除去できるものであればよく、適宜選択すればよい。 In step S5, the liquid mixture obtained in step S4 is shaken, and in step S6, the liquid mixture is filtered. The type of filter such as filter paper used for filtration is not particularly limited as long as it can remove the residue of the mixed solution, and may be appropriately selected.
ステップＳ７では、ステップＳ６で得られた濾液を電気化学測定に供する。 In step S7, the filtrate obtained in step S6 is subjected to electrochemical measurement.
電気化学測定においては、標準添加法を用いるとよい。例えば、検液のみでの測定に加え、標準液を２回添加し、３つの電位−電流特性曲線を求め、各波形におけるピーク面積を算出し、標準液の添加濃度に対して検量線を作成することで、検液中の濃度を算出することができる。具体的にピーク面積は、測定対象物質、測定対象物質濃度及び電極材料によって異なるが、本発明では、−０．６２Ｖと−０．５８Ｖの間の最小電流値と−０．５Ｖと−０．４Ｖの間の最小電流値を示す点を直線で結び、この直線と電位−電流特性曲線とで囲まれる面積を算出した。 In the electrochemical measurement, a standard addition method may be used. For example, in addition to the measurement using only the test solution, the standard solution is added twice, three potential-current characteristic curves are obtained, the peak area in each waveform is calculated, and a calibration curve is created for the added concentration of the standard solution By doing so, the concentration in the test solution can be calculated. Specifically, the peak area varies depending on the measurement target substance, the measurement target substance concentration, and the electrode material, but in the present invention, the minimum current value between −0.62 V and −0.58 V, −0.5 V and −0. Points indicating the minimum current value between 4V were connected by a straight line, and an area surrounded by this straight line and the potential-current characteristic curve was calculated.
以下に、具体的な実施例を挙げて本発明に係るカドミウム濃度測定方法について詳細に説明する。なお、本発明に係るカドミウム濃度測定方法及び、カドミウム濃度測定装置は、この実施例に限定されるものではない。
（実施例１）
玄米標準試料として、独立行政法人国立環境研究所から３種類の既知カドミウム濃度の玄米標準試料を入手した。それぞれのカドミウム濃度は、０．０２３ｍｇ／ｋｇ、０．３２ｍｇ／ｋｇ、１．８２ｍｇ／ｋｇであった。
Hereinafter, the cadmium concentration measuring method according to the present invention will be described in detail with specific examples. The cadmium concentration measuring method and the cadmium concentration measuring apparatus according to the present invention are not limited to this embodiment.
Example 1
As brown rice standard samples, three types of known cadmium brown rice standard samples were obtained from the National Institute for Environmental Studies. The respective cadmium concentrations were 0.023 mg / kg, 0.32 mg / kg, and 1.82 mg / kg.
玄米粉末標準試料は、米の微量元素を定量する際に、本試料を用いて測定値及び測定分析法の正確さが評価できることを目的として調製された環境標準試料である。本標準試料は、カドミウムの濃度が異なる３種類の試料（Ｃｄ低、中、高レベル）で一組となっている。玄米粉末標準試料は、元素含有量に関する標準試料であり、１３元素に対して保証値（ｃｅｒｔｉｆｉｅｄ ｖａｌｕｅ）及び９元素に対して参考値（ｒｅｆｅｒｅｎｃｅ ｖａｌｕｅ）が定められている。 The brown rice powder standard sample is an environmental standard sample prepared for the purpose of evaluating the accuracy of measurement values and measurement analysis methods using this sample when quantifying trace elements in rice. This standard sample is a set of three types of samples (Cd low, medium and high levels) with different cadmium concentrations. The brown rice powder standard sample is a standard sample relating to the element content. A certified value is set for 13 elements and a reference value is set for 9 elements.
実施例１では、本発明に係る測定方法を用いて、玄米中のカドミウム濃度を測定した。図１を参照して、詳細に説明する。 In Example 1, the cadmium concentration in brown rice was measured using the measurement method according to the present invention. This will be described in detail with reference to FIG.
独立行政法人国立環境研究所から標準玄米試料を入手した。この標準玄米試料は、既に、図１の測定フロー図のステップ１が完了している粉末状の試料である。この試料を１ｇ秤量した（ステップＳ２）。 Standard brown rice samples were obtained from the National Institute for Environmental Studies. This standard brown rice sample is a powdery sample in which step 1 in the measurement flow diagram of FIG. 1 has already been completed. 1 g of this sample was weighed (step S2).
そして、ステップＳ２で秤量した粉砕された玄米を蒸発皿またはルツボに入れ、電気炉で強熱灰化処理を行った（ステップＳ３）。 Then, the ground brown rice weighed in step S2 was put into an evaporating dish or crucible and subjected to an intense ashing process in an electric furnace (step S3).
さらに、ステップＳ３で強熱灰化処理した蒸発皿またはルツボをデシケータ内に移し、放冷後、５０ｍＬの蓋付きガラス容器に内容物を移し、１モル／Ｌの塩酸を２０ｍＬ加えた（ステップＳ４）。 Further, the evaporating dish or crucible subjected to ashing in step S3 was transferred into a desiccator, allowed to cool, then the contents were transferred to a 50 mL lidded glass container, and 20 mL of 1 mol / L hydrochloric acid was added (step S4). ).
このガラス容器を振とう器で１５０ｒｐｍの速度で１時間振とうした（ステップＳ５）後、５Ｃのろ紙で濾過を行い（ステップＳ６）、濾液を必要量５０ｍＬのメスフラスコに入れて、２．５ｍＬの酸薬液、２．５ｍＬの試薬液の順番に添加した後、蒸留水で５０ｍＬにメスアップした。 The glass container was shaken with a shaker at a speed of 150 rpm for 1 hour (step S5), then filtered with 5C filter paper (step S6), and the filtrate was put into a required volume 50 mL volumetric flask to obtain 2.5 mL. Were added in the order of 2.5 mL of the reagent solution and 2.5 mL of the reagent solution, and the volume was made up to 50 mL with distilled water.
これを北斗電工(株)製の電気化学測定装置ＦＩＥＬＤＥＲ(型式：ＨＯＥ−１００)で電流値を計測した（ステップＳ７）。 The electric current value of this was measured with an electrochemical measuring device FIELDER (model: HOE-100) manufactured by Hokuto Denko Corporation (step S7).
以下に、ステップ７で用いた酸薬液及び試薬液の調製例を示す。
・酸薬液の調製法
濃塩酸１２０ｍＬを蒸留水で１Ｌにメスアップして酸薬液を調製した。
・試薬液の調製法
塩化カリウム：２２３．６５ｇ
水酸化ナトリウム：５７．１４ｇ
酢酸：８．６ｍＬ
酢酸ナトリウム：２８．７ｇ
以上を１Ｌのメスフラスコに入れて蒸留水で１Ｌにメスアップして試薬液を調製した。
Hereinafter, preparation examples of the acid chemical solution and the reagent solution used in Step 7 are shown.
-Preparation method of acid drug solution An acid drug solution was prepared by measuring 120 mL of concentrated hydrochloric acid to 1 L with distilled water.
-Preparation method of reagent solution Potassium chloride: 223.65g
Sodium hydroxide: 57.14g
Acetic acid: 8.6 mL
Sodium acetate: 28.7g
The above was put into a 1 L measuring flask and made up to 1 L with distilled water to prepare a reagent solution.
電気化学測定装置は、作用電極として銅電極を、対電極は白金電極、参照電極は銀／塩化銀電極を使用した。 In the electrochemical measurement apparatus, a copper electrode was used as a working electrode, a platinum electrode was used as a counter electrode, and a silver / silver chloride electrode was used as a reference electrode.
計測結果を図２、図３に示す。図２は電位−電流特性曲線、図３は標準添加法による絶対検量線である。図２の電位−電流特性曲線において、−０．５３Ｖのピークがカドミウムのピークである。また、図２には、３種類の電位−電流特性曲線（０ｍｇ／Ｌ、０．０２ｍｇ／Ｌ、０．０４ｍｇ／Ｌ）が示されている。これは、標準添加法において標準となる溶液を１００μＬ添加した際の試料液の電位−電流特性曲線を表示するものである（図４、７、１３−１８も同様）。 The measurement results are shown in FIGS. FIG. 2 shows a potential-current characteristic curve, and FIG. 3 shows an absolute calibration curve obtained by the standard addition method. In the potential-current characteristic curve of FIG. 2, the peak at −0.53 V is the cadmium peak. FIG. 2 shows three types of potential-current characteristic curves (0 mg / L, 0.02 mg / L, and 0.04 mg / L). This displays the potential-current characteristic curve of the sample solution when 100 μL of a standard solution is added in the standard addition method (the same applies to FIGS. 4, 7, and 13-18).
図４は、３種類のカドミウム標準液（０．０１、０．０３、０．０５ｍｇ／Ｌ）を測定した電位−電流特性曲線で、−０．５３Ｖのカドミウムのピークがカドミウム濃度の増加と共にピーク値が増大することがわかる。 FIG. 4 is a potential-current characteristic curve obtained by measuring three types of cadmium standard solutions (0.01, 0.03, 0.05 mg / L). The peak of cadmium at −0.53 V increases with an increase in cadmium concentration. It can be seen that the value increases.
図５は、カドミウム標準液濃度とＦＩＥＬＤＥＲの計測値の関係を示したものである。Ｒ2は０．９９３３、回帰直線の傾きが０．９７８３で１に近い値を示しており、電気化学測定法でカドミウム濃度を精度良く測定できることを示している。 FIG. 5 shows the relationship between the cadmium standard solution concentration and the measured value of FIELDER. R 2 is 0.9933, and the slope of the regression line is 0.9783, which is close to 1, indicating that the cadmium concentration can be measured with high accuracy by the electrochemical measurement method.
図６は、図１に示したカドミウム測定方法において、強熱灰化処理工程（ステップＳ３）を省いた測定方法で、独立行政法人国立環境研究所から入手した３種類の玄米標準試料を誘導結合プラズマ発光分析装置（ＩＣＰ）で測定した結果である。 FIG. 6 is a measurement method in which the ignition ashing process (step S3) is omitted in the cadmium measurement method shown in FIG. 1, and three types of brown rice standard samples obtained from the National Institute for Environmental Studies are inductively coupled. It is the result measured by the plasma emission analyzer (ICP).
Ｒ2は０．９９７８、回帰直線の傾きが０．９６７５で１に近い値を示しており、測定時間の短時間化だけを考慮するのであれば、高価で、大型の据置き型の機器分析装置により、公定法では約５日間かかる測定時間を約２時間に短縮できることを示している。 R 2 is 0.9978, slope of the regression line indicates a value close to 1 at 0.9675, if considering the short time of the measurement time, and expensive, large stationary instrumental analysis The apparatus shows that the official method can reduce the measurement time, which takes about 5 days, to about 2 hours.
しかし、図１の強熱灰化処理工程を省いた測定フローは、電気化学測定法により玄米中のカドミウム濃度の測定ができなかった。これは、図７に示すように、カドミウムの検出ピークである−０．５３Ｖにピークの差異が現れないので、標準添加法による正常な電位−電流特性曲線が得られないため絶対検量線が作成できず、カドミウム濃度が算出できなかったためである。 However, the measurement flow without the ignition ashing process in FIG. 1 was unable to measure the cadmium concentration in the brown rice by the electrochemical measurement method. This is because, as shown in FIG. 7, since no difference in peak appears in the cadmium detection peak of -0.53 V, a normal potential-current characteristic curve cannot be obtained by the standard addition method, so an absolute calibration curve is created. This is because the cadmium concentration could not be calculated.
独立行政法人国立環境研究所から分譲された玄米標準試料は、カドミウム含有量が低濃度の試料（Ｌ：濃度０．０２３ｍｇ／ｋｇ）、中濃度の試料（Ｍ：濃度０．３２ｍｇ／ｋｇ）、そして高濃度の試料（Ｈ：濃度１．８２ｍｇ／ｋｇ）の３種類である。 The brown rice standard samples distributed from the National Institute for Environmental Studies are samples with low cadmium content (L: concentration 0.023 mg / kg), medium concentration samples (M: concentration 0.32 mg / kg), There are three types of high-concentration samples (H: concentration 1.82 mg / kg).
これら３種類の玄米標準試料には、亜鉛、塩素、カリウム、臭素、水銀、セレン、ナトリウム、ルビジウム等が不純物として含まれており、これら不純物のいずれか、または、これら不純物が複合してカドミウム濃度測定の妨害となっていると考えられる。表１に玄米標準試料中に含まれるそれぞれの元素の含有量と融点及び沸点を示す。 These three types of brown rice standard samples contain zinc, chlorine, potassium, bromine, mercury, selenium, sodium, rubidium, etc. as impurities, and any one of these impurities or a combination of these impurities results in a cadmium concentration. This is considered to be an obstacle to the measurement. Table 1 shows the content, melting point and boiling point of each element contained in the brown rice standard sample.
カドミウムの沸点は７６５℃であるので、７６５℃以上に加熱するとカドミウムは気化して空気中に飛散してしまう。したがって、亜鉛の融点以上でカドミウムの沸点以下の温度で加熱すれば、不純物の結合がほどけて分離できる可能性があると考えられる。 Since the boiling point of cadmium is 765 ° C., when heated to 765 ° C. or higher, cadmium is vaporized and scattered in the air. Therefore, if heating is performed at a temperature not lower than the melting point of zinc and not higher than the boiling point of cadmium, it is considered that there is a possibility that the bonding of impurities is released and separation is possible.
（１)カドミウム濃度測定における強熱灰化温度の影響
そこで、玄米標準試料（カドミウム濃度：１．８２ｍｇ／ｋｇを用いて、強熱灰化時間を６０分として、強熱灰化温度を０、１２０、２００、４００、４５０、５００、５５０、６００、６５０、７００、７５０、８００、１０００℃に変化してカドミウム濃度を計測した。計測結果を図８に示す。
(1) Influence of ignition ashing temperature in cadmium concentration measurement Therefore, using a brown rice standard sample (cadmium concentration: 1.82 mg / kg, ignition ashing time is 60 minutes, ignition ashing temperature is 0, The cadmium concentration was measured while changing to 120, 200, 400, 450, 500, 550, 600, 650, 700, 750, 800, and 1000 ° C. The measurement result is shown in FIG.
図８より、強熱灰化温度を亜鉛の融点以上、カドミウムの沸点以下で行うと精度よくカドミウム濃度を測定できることがわかる。そして、強熱灰化温度を５３０〜６３０℃とすることでより精度よくカドミウム濃度を測定することができる。同一試料を機器分析装置のＩＣＰでも測定したが、本発明に係るカドミウム測定方法による測定結果を支持する結果であった。 It can be seen from FIG. 8 that the cadmium concentration can be measured with high accuracy when the ignition temperature is higher than the melting point of zinc and lower than the boiling point of cadmium. And a cadmium density | concentration can be measured more accurately by setting an ignition ashing temperature to 530-630 degreeC. Although the same sample was also measured by ICP of the instrument analyzer, it was a result supporting the measurement result by the cadmium measurement method according to the present invention.
（２）カドミウム濃度測定における強熱灰化時間の影響
玄米標準試料（カドミウム濃度：１．８２ｍｇ／ｋｇ）を用い、強熱灰化温度を６００℃として、強熱灰化時間を０、１０、２０、３０、４０、５０、６０、９０、１２０、１５０、１８０分に変化してカドミウム濃度を計測した。結果を図９に示す。
(2) Influence of ignition ashing time in cadmium concentration measurement Using a brown rice standard sample (cadmium concentration: 1.82 mg / kg), the ignition ashing temperature is 600 ° C., and the ignition ashing time is 0, 10; The cadmium concentration was measured at 20, 30, 40, 50, 60, 90, 120, 150, and 180 minutes. The results are shown in FIG.
図９から、強熱灰化時間は、４５〜９０分で行えば玄米中からほぼ１００パーセントのカドミウムが抽出できることがわかる。 From FIG. 9, it can be seen that if the ignition time is 45 to 90 minutes, almost 100% of cadmium can be extracted from the brown rice.
（３）カドミウム濃度測定における試験液のｐＨの影響
電気化学測定法では、試験液のｐＨが測定精度に大きく影響するので、カドミウムの溶出量試験に及ぼすｐＨの影響について試験した。試験方法を以下に示す。
(3) Effect of pH of test solution in cadmium concentration measurement In the electrochemical measurement method, since the pH of the test solution greatly affects the measurement accuracy, the influence of pH on the cadmium elution amount test was tested. The test method is shown below.
まず、２．５ｍｇ／Ｌのカドミウム溶液を調製し、標準液とした。 First, a 2.5 mg / L cadmium solution was prepared and used as a standard solution.
２．５ｍｇ／Ｌカドミウム溶液の調製法は、カドミウム標準液１０００ｍｇ／Ｌ、０．２５ｍＬと濃塩酸０．６ｍＬを１モル／Ｌの塩酸で１００ｍＬにメスアップした。
The 2.5 mg / L cadmium solution was prepared by measuring
試験液は、５０ｍＬメスフラスコに約２５ｍＬの蒸留水を入れ、これに２．５ｍｇ／Ｌカドミウム溶液を６００μＬ添加した。これを必要量用意する。 About 25 mL of distilled water was placed in a 50 mL volumetric flask, and 600 μL of a 2.5 mg / L cadmium solution was added thereto. Prepare the required amount of this.
それぞれのメスフラスコに、ｐＨを調整するため、２Ｎの水酸化ナトリウムを０、５０、１００、２００、３００、４００、５００、６００μＬ添加し、２．５ｍＬの酸薬液、２．５ｍＬの試薬液の順番に添加した後、５０ｍＬにメスアップした。 In order to adjust the pH to each volumetric flask, 0, 50, 100, 200, 300, 400, 500, 600 μL of 2N sodium hydroxide was added, and 2.5 mL of acid chemical solution and 2.5 mL of reagent solution were added. After adding in order, it was made up to 50 mL.
さらに、それぞれのメスフラスコに、２Ｎの水酸化ナトリウムを５０μＬ添加した後、４Ｎの塩酸を２０、５０、１００、２００μＬ添加して、低ｐＨ溶液を調製した。 Further, 50 μL of 2N sodium hydroxide was added to each volumetric flask, and then 20, 50, 100, and 200 μL of 4N hydrochloric acid was added to prepare a low pH solution.
各試験液をＦＩＥＬＤＥＲ専用のセルに移し、電流値を測定し、カドミウム濃度を算出したカドミウム濃度測定結果を図１０に示す。 FIG. 10 shows the cadmium concentration measurement result obtained by transferring each test solution to a cell dedicated to FIELDER, measuring the current value, and calculating the cadmium concentration.
調製された５０ｍＬの試験液は、２．５ｍｇ／Ｌカドミウム溶液を６００μＬ添加しているので、カドミウム濃度は０．０３ｍｇ／Ｌである。図１０の測定結果では、ｐＨが３．５以下または５．５以上になると真値から外れることを示している。したがって、本発明に係る電気化学測定法でカドミウム濃度を測定する場合には、ｐＨは３．５〜５．５の間で測定すると精度よくカドミウム濃度を測定することがわかる。そして、ｐＨを４．０〜５．０とするとより精度よく測定できることがわかる。 Since the prepared 50 mL test solution is added with 600 μL of a 2.5 mg / L cadmium solution, the cadmium concentration is 0.03 mg / L. The measurement results in FIG. 10 indicate that the pH value deviates from the true value when the pH value is 3.5 or lower or 5.5 or higher. Therefore, when measuring the cadmium concentration by the electrochemical measurement method according to the present invention, it can be seen that the cadmium concentration can be measured with high accuracy when the pH is measured between 3.5 and 5.5. And when pH is set to 4.0-5.0, it turns out that it can measure more accurately.
（４）電気化学測定法による玄米標準試料中のカドミウム濃度の測定
図１の測定フローで、独立行政法人国立環境研究所から入手した３種類の玄米標準試料を電気化学測定法で測定した結果を図１１に示す。
(4) Measurement of cadmium concentration in brown rice standard sample by electrochemical measurement method In the measurement flow of Fig. 1, the results of measuring three types of brown rice standard samples obtained from the National Institute for Environmental Studies by electrochemical measurement method are shown. As shown in FIG.
Ｒ2は０．９９９９、回帰直線の傾きが１．０４５９で１に近い値を示しており、十分な測定精度を有していることを示している。 R 2 is 0.9999, and the slope of the regression line is 1.0459, indicating a value close to 1, indicating that the measurement accuracy is sufficient.
（５）電気化学測定法によるカドミウム濃度の測定精度
図１の測定フローで、独立行政法人国立環境研究所から入手した玄米標準試料（カドミウム濃度：１．８２ｍｇ／ｋｇ）を電気化学測定法で繰り返し測定した。
(5) Measurement accuracy of cadmium concentration by electrochemical measurement method In the measurement flow of Fig. 1, the brown rice standard sample (cadmium concentration: 1.82 mg / kg) obtained from the National Institute for Environmental Studies was repeatedly measured by the electrochemical measurement method. It was measured.
玄米標準試料は１ｇ秤量し、１モル／Ｌの塩酸を２０ｍＬ、濾液を４ｍＬ、強熱灰化温度を６００℃、強熱灰化時間を１時間として測定した。カドミウム濃度の測定結果を表２に示す。表２に示すように、変動係数（ＣＶ）は４．７パーセントとなり、精度良くカドミウム濃度が測定できることを示している。 1 g of brown rice standard sample was weighed and measured with 20 mL of 1 mol / L hydrochloric acid, 4 mL of filtrate, ignition ashing temperature of 600 ° C., and ignition ashing time of 1 hour. Table 2 shows the measurement results of the cadmium concentration. As shown in Table 2, the coefficient of variation (CV) is 4.7%, which indicates that the cadmium concentration can be measured with high accuracy.
（６）カドミウム濃度測定における有機物の影響
カドミウム濃度測定における有機物の影響を調べるために、図１２に示す測定フロー図に従って、澱粉を混合したカドミウム標準液を調製し、カドミウム濃度測定を行った。カドミウム濃度測定結果を図１３に示す。
(6) Influence of organic substance in cadmium concentration measurement In order to investigate the influence of organic substance in cadmium concentration measurement, a cadmium standard solution in which starch was mixed was prepared according to the measurement flowchart shown in FIG. 12, and cadmium concentration measurement was performed. The results of measuring the cadmium concentration are shown in FIG.
カドミウムのピーク電圧は、銅電極を作用電極に使用した場合、−０．５３Ｖであり、図１３に示すように、この電圧に於けるピークが明確に測定されている。 The peak voltage of cadmium is −0.53 V when a copper electrode is used as a working electrode, and the peak at this voltage is clearly measured as shown in FIG.
したがって、測定対象となる溶液中に澱粉が混合していても、カドミウムのピークを阻害しないので、澱粉のような有機物を単に添加するだけならばカドミウム濃度測定に影響を及ぼさないといえる。 Therefore, even if starch is mixed in the solution to be measured, the peak of cadmium is not inhibited. Therefore, it can be said that the cadmium concentration measurement is not affected if an organic substance such as starch is simply added.
（７）各食品でのカドミウム濃度測定
本発明に係るカドミウム濃度測定装置により、各食品のカドミウム濃度を測定した結果を図１４〜１８に示す。
(7) Cadmium density | concentration measurement in each foodstuff The result of having measured the cadmium density | concentration of each foodstuff with the cadmium density | concentration measuring apparatus which concerns on this invention is shown to FIGS.
測定対象として、アサリ、ホタテ貝、クルミ、カシュウナッツ、マカデミアンナッツを選択し、図１の測定フローに従って各食品中のカドミウム濃度を測定した。なお、粉砕方法（ステップＳ１）は、各食品によって異なる方法を用いた。すなわち、アサリは、貝を剥いてまな板上で包丁を用いて細かくみじん切りにし、蒸しホタテ貝は、そのまままな板上で包丁を用いて細かくみじん切りにした。また、クルミ、カシュウナッツ、マカデミアンナッツは、市販されているミックスナッツから選別後、それぞれコーヒーミルで約１０秒間粉砕した。それぞれの食品中のカドミウム濃度測定結果を表３に示す。なお、同一試料をＩＣＰで測定した結果も本発明に係るカドミウム測定方法による測定結果を支持する結果であった。 Clams, scallops, walnuts, cashew nuts, and macadamian nuts were selected as measurement targets, and the cadmium concentration in each food was measured according to the measurement flow of FIG. In addition, the grinding | pulverization method (step S1) used the method which changes with each foodstuff. That is, clams were peeled off and finely chopped with a knife on a cutting board, and steamed scallops were finely chopped with a knife on a cutting board. In addition, walnuts, cashew nuts, and macadamian nuts were selected from commercially available mixed nuts and then ground for about 10 seconds in a coffee mill. Table 3 shows the results of measuring the cadmium concentration in each food. In addition, the result of measuring the same sample by ICP was a result supporting the measurement result by the cadmium measurement method according to the present invention.
表３に示すように、本発明に係るカドミウム濃度測定方法により、各種食品中のカドミウム濃度も測定できることがわかる。 As shown in Table 3, it can be seen that the cadmium concentration in various foods can also be measured by the cadmium concentration measurement method according to the present invention.
以上述べたように、本発明に係るカドミウム濃度測定方法、及びカドミウム濃度測定装置によれば、食品中のカドミウムを専門知識と熟練を要する煩雑な操作や８種類以上の複数の試薬を使用せず、簡便に測定することができる。 As described above, according to the cadmium concentration measuring method and the cadmium concentration measuring apparatus according to the present invention, cadmium in food is used without complicated operations requiring specialized knowledge and skill and using a plurality of eight or more types of reagents. It can be measured easily.
また、食品中のカドミウム濃度を３時間程度の短時間で、精度よく測定することができる。 In addition, the cadmium concentration in the food can be accurately measured in a short time of about 3 hours.
したがって、高価で、大型の据置き型の機器分析装置を使用せず、短時間に高精度の測定が可能な電気化学測定法により現場でのオンサイト測定が可能であるため、カドミウムに汚染された玄米等の農作物が市場に流通する危険を防止する用途をはじめとして種々利用できる。 Therefore, it is possible to perform on-site measurement in the field using an electrochemical measurement method that enables high-precision measurement in a short time without using an expensive and large-sized stationary instrument analyzer. It can be used for a variety of purposes, including preventing the danger of agricultural products such as brown rice being distributed to the market.
Claims (7)
前記食品を強熱灰化し、
前記強熱灰化した食品を酸と混合し、前記混合された混合液から溶液を分離し、
前記溶液を電気化学測定法に供する
ことを特徴とするカドミウム測定方法。 A method for measuring cadmium in food,
The food is ignited with high heat,
Mixing the heat ashed food with acid, separating the solution from the mixed mixture,
A cadmium measurement method, wherein the solution is subjected to an electrochemical measurement method.
ことを特徴とする請求項１に記載のカドミウム測定方法。 The cadmium measurement method according to claim 1, wherein the electrochemical measurement method is anodic stripping voltammetry.
ことを特徴とする請求項１または請求項２に記載のカドミウム測定方法。 The cadmium measurement method according to claim 1, wherein the working electrode used in the electrochemical measurement method is a copper electrode.
ことを特徴とする請求項１から請求項３のいずれか１項に記載のカドミウム測定方法。 The cadmium measuring method according to any one of claims 1 to 3, wherein the ignition time is 45 minutes to 90 minutes.
ことを特徴とする請求項１から請求項４のいずれか１項に記載のカドミウム測定方法。 5. The cadmium measurement method according to claim 1, wherein the ignition ashing temperature is not lower than the melting point of zinc and not higher than the boiling point of cadmium.
ことを特徴とする請求項１から請求項５のいずれか１項に記載のカドミウム測定方法。 The cadmium measurement method according to any one of claims 1 to 5, wherein the pH of the solution is adjusted from 3.5 to 5.5.
前記食品を強熱灰化する強熱灰化手段と、
前記強熱灰化手段により灰化された食品と酸を混合し、前記混合された混合から分離された溶液を収納する手段と、
前記溶液に、作用電極としての銅電極と、対電極を浸漬する手段と、
前記作用電極と前記対電極との間に前記溶液中のカドミウムが前記作用電極上に析出する電圧を印加する手段と、
前記作用電極と前記対電極との間に前記作用電極上に析出したカドミウムが溶出する電圧を印加する手段と、
前記作用電極と前記対電極との間に流れる電流を検出する手段と、を備えた
ことを特徴とするカドミウム測定装置。 An apparatus for measuring cadmium in food,
A heat ashing means for ashing the food;
Means for mixing the food and acid ashed by the ignition ashing means, and storing the solution separated from the mixed mixture;
A copper electrode as a working electrode and a means for immersing a counter electrode in the solution;
Means for applying a voltage at which cadmium in the solution is deposited on the working electrode between the working electrode and the counter electrode;
Means for applying a voltage at which cadmium deposited on the working electrode elutes between the working electrode and the counter electrode;
And a means for detecting a current flowing between the working electrode and the counter electrode.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012137314A1 (en) * | 2011-04-06 | 2012-10-11 | 株式会社明電舎 | Method and apparatus for measuring cadmium in food |
| JP2014130031A (en) * | 2012-12-28 | 2014-07-10 | Horiba Ltd | Electrochemical analytical method, electrochemical analysis device, and reagent set |
| WO2020196587A1 (en) | 2019-03-28 | 2020-10-01 | 日東電工株式会社 | Electrode and electrochemical measurement system |
| CN112098482A (en) * | 2020-09-09 | 2020-12-18 | 南京腾森分析仪器有限公司 | Method for detecting lead in food |
| CN113219027A (en) * | 2021-05-07 | 2021-08-06 | 安徽大学 | Method for quantitatively detecting potassium iodate |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000241388A (en) * | 1999-02-25 | 2000-09-08 | Kurabo Ind Ltd | Simultaneous quick measuring method for trace concentration of plural metals |
| JP2006284378A (en) * | 2005-03-31 | 2006-10-19 | National Institute Of Advanced Industrial & Technology | Simplified analysis method of heavy metal in agricultural product |
| JP2007309802A (en) * | 2006-05-18 | 2007-11-29 | Hokuto Denko Kk | Solution analyzer and analysis method |
| JP2009168650A (en) * | 2008-01-17 | 2009-07-30 | Sekisui Chem Co Ltd | Cartridge type electrochemical analysis device and method |
-
2009
- 2009-10-16 JP JP2009239664A patent/JP5319485B2/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000241388A (en) * | 1999-02-25 | 2000-09-08 | Kurabo Ind Ltd | Simultaneous quick measuring method for trace concentration of plural metals |
| JP2006284378A (en) * | 2005-03-31 | 2006-10-19 | National Institute Of Advanced Industrial & Technology | Simplified analysis method of heavy metal in agricultural product |
| JP2007309802A (en) * | 2006-05-18 | 2007-11-29 | Hokuto Denko Kk | Solution analyzer and analysis method |
| JP2009168650A (en) * | 2008-01-17 | 2009-07-30 | Sekisui Chem Co Ltd | Cartridge type electrochemical analysis device and method |
Non-Patent Citations (3)
| Title |
|---|
| JPN6013013404; Ｓａｍｕｅｌ Ｂ． Ａｄｅｌｏｊｕ: 'Ｃｏｍｐａｒｉｓｏｎ ｏｆ Ｓｏｍｅ Ｗｅｔ Ｄｉｇｅｓｔｉｏｎ ａｎｄ Ｄｒｙ Ａｓｈｉｎｇ Ｍｅｔｈｏｄｓ ｆｏｒ Ｖｏｌｔａｍｍｅｔｒｉｃ Ｔｒａｃｅ Ｅｌｅｍｅｎｔ Ａｎａｌｙｓｉｓ' Ａｎａｌｙｓｔ Ｖｏｌ．１１４, 1989, ｐ．４５５-４６１ * |
| JPN6013013406; Ｒａｙｍｏｎｄ Ｊ． Ｇａｊａｎ， ｅｔ ａｌ．: 'Ｄｅｔｅｒｍｉｎａｔｉｏｎ ｏｆ Ｌｅａｄ ａｎｄ Ｃａｄｍｉｕｍ ｉｎ Ｆｏｏｄｓ ｂｙ Ａｎｏｄｉｃ Ｓｔｒｉｐｐｉｎｇ Ｖｏｌｔａｍｍｅｔｒｙ： Ｉ． Ｄｅｖｅｌｏｐｍｅｎｔ ｏｆ Ｍｅｔｈｏｄ' Ｊ．Ａｓｓｏｃ． Ｏｆｆ． Ａｎａｌ． Ｃｈｅｍ． Ｖｏｌ．６５， Ｎｏ．４, 1982, ｐ．９７０-９７７ * |
| JPN6013013407; ＪＯＨＮ Ｗ． ＪＯＮＥＳ ｅｔ ａｌ．: 'Ｄｒｙ Ａｓｈ-Ｖｏｌｔａｍｍｅｔｒｉｃ Ｄｅｔｅｒｍｉｎａｔｉｏｎ ｏｆ Ｃａｄｍｉｕｍ， Ｃｏｐｐｅｒ， Ｌｅａｄ， ａｎｄ Ｚｉｎｃ ｉｎ Ｆｏｏｄ' Ｊｏｕｒｎａｌ ｏｆ ｔｈｅ ＡＯＡＣ Ｖｏｌ．６０、Ｎｏ．４, 1977, ｐ．８２６-８３２ * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012137314A1 (en) * | 2011-04-06 | 2012-10-11 | 株式会社明電舎 | Method and apparatus for measuring cadmium in food |
| JP2014130031A (en) * | 2012-12-28 | 2014-07-10 | Horiba Ltd | Electrochemical analytical method, electrochemical analysis device, and reagent set |
| WO2020196587A1 (en) | 2019-03-28 | 2020-10-01 | 日東電工株式会社 | Electrode and electrochemical measurement system |
| KR20210144722A (en) | 2019-03-28 | 2021-11-30 | 닛토덴코 가부시키가이샤 | Electrode and Electrochemical Measurement Systems |
| CN112098482A (en) * | 2020-09-09 | 2020-12-18 | 南京腾森分析仪器有限公司 | Method for detecting lead in food |
| CN112098482B (en) * | 2020-09-09 | 2023-01-10 | 南京腾森分析仪器有限公司 | Method for detecting lead in food |
| CN113219027A (en) * | 2021-05-07 | 2021-08-06 | 安徽大学 | Method for quantitatively detecting potassium iodate |
| CN113219027B (en) * | 2021-05-07 | 2023-07-21 | 安徽大学 | Method for quantitatively detecting potassium iodate |
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