Toshihiro Nagayama

Meiji Pharmaceutical University

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Maki Kobayashi

Miyagi Prefectural Hospital Organization

Yasuhiro Tamura

Tokyo Metropolitan Institute of Public Health

Kazuo YASUDA

Toyo Institute of Food Technology

Akihiro IBE

Jissen Women's University

Kazuo Saito

Japan Agency for Marine-Earth Science and Technology

Ichiro TAKANO

Kogakuin University

Hisashi KAMIMURA

Saitama Medical University

Motohiro NISHIJIMA

Jissen Women's University

Yasuta Naoi

Tokyo Metropolitan Institute of Public Health

Hirofumi USHIYAMA

Tokyo Metropolitan Institute of Public Health

Cooperative Institutions

Tokyo Metropolitan Institute of Public Health

National Institute of Health Sciences

Japan Society for the Promotion of Science

The University of Tokyo

Nagoya University

Hokkaido University

Kyoto University

Japan Food Research Laboratories

Osaka University

University of Tsukuba

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Hygienic studies on "health food". II.

Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi) (1986)

Kazuo YASUDA Motohiro NISHIJIMA Kazuo Saito Hisashi KAMIMURA Akihiro IBE

10.3358/shokueishi.27.302

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Citations (1)

Gas Chromatographic Determination of Propamocarb in Agricultural Commodities

Journal of AOAC International (1996)

Toshihiro Nagayama Maki Kobayashi Hiroko Shioda Toshio Tomomatsu

Abstract A simple and efficient gas chromatographic (GC) method is described for quantitative determination of propamocarb in agricultural commodities. Propamocarb is extracted into acetone–water (or acidified solvent for dry products) and then cleaned up by extraction with diethyl ether. The analyte is extracted from the aqueous fraction under basic conditions with diethyl ether and then analyzed by GC with nitrogen–phosphorus detection. The minimum detection limit is 0.01 μg/g in original samples (signal-to-noise ratio > 5). Recovery of propamocarb spiked at 0.1 μg/g into various samples is >75%, except for lettuce (41%).

Diethyl ether

Fraction (chemistry)

10.1093/jaoac/79.3.769

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Citations (6)

Pesticide Residues in Domestic Raw Agricultural Commodity

Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi) (1994)

Toshihiro Nagayama Maki Kobayashi Hiroko Shioda Y. TAMURA

[in Japanese]

Commodity chemicals

10.3358/shokueishi.35.652

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Citations (2)

Transfer of the Pesticide Residues to Crops via Cardboard Boxes

Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi) (2009)

Keiko Iwakoshi Ichiro TAKANO Maki Kobayashi Kenji OHTSUKA Yasuhiro Tamura

農産物の流通過程において再利用されるダンボール箱に，農産物に残留した農薬の移行が認められた．このダンボール箱を介して農薬が他の農産物へ移行する可能性を調査するため，モデル実験を行った．かんきつ類の箱に野菜を入れた場合を想定し，こすり付けるなどの過酷な条件下，表面ふき取りによる測定で検討を加えたところ，検討した3農薬の平均値は，グレープフルーツで添加量の6.2%，みかんで 0.57% がほうれんそうに移行したと算出された．今回の結果は，最大に移行した場合に相当すると考えられ，実際の農薬移行量は，より低いと思われるが，農薬がダンボール箱を介して他の農産物に移行する可能性は否定できない．流通過程で非意図的に農薬の移染が起こることが示唆され，このような農薬移染を防止する対策が必要である．

cardboard

10.3358/shokueishi.50.223

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Reverse-Phase Liquid Chromatographic Determination of Paraquat and Diquat in Agricultural Products

Journal of AOAC INTERNATIONAL (1987)

Toshihiro Nagayama Toshio Maki Kimiko KAN Mami Iida Taichiro Nishima

A simple, rapid, highly sensitive liquid chromatographic method is described for the quantitative determination of paraquat and diquat residues in agricultural products. Paraquat and diquat are extracted with hot dilute hydrochloric acid and are cleaned up on an Amberlite CG-50 column, followed by reverse-phase liquid chromatography on an NH2 column, with ultraviolet detection at 257 nm (paraquat) and 310 nm (diquat). The minimum detectable concentration of both paraquat and diquat was 0.5 ng per injection, which corresponds to a lower detection limit of approximately 0.02 microgram/g in the original samples. Recoveries of paraquat and diquat added to various samples were greater than 79%, and averaged 91 and 90%, respectively, at the 0.1 and 1.0 microgram/g spiking levels.

Diquat

Amberlite

Hydrochloric acid

10.1093/jaoac/70.6.1008

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Citations (2)

Performance Study of Analytical Method for Ethoxyquin in Fruit.

Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi) (2002)

Kumiko Sasaki Takashi Tatsuno Takakazu NOMURA Tsuyoshi IMAZAWA Osamu UTSUNOMIYA

日焼け防止剤エトキシキン(ET)の食品衛生法告示試験法を改良した分析法について共同実験を行って評価した．この分析法ではETの分解を抑制するために，ホモジナイズ時にチオ尿素を添加し，試験溶液に酸化防止剤BHTを添加した．また，抽出効率を上げるためにヘキサンに代えてアセトンを抽出溶媒とした．6分析機関で 0.2 μg/g のETを添加したりんご，洋なし，日本なしを分析したときの平均回収率は 83.0～85.3%，併行再現性及び室間再現性の相対標準偏差はそれぞれ 3.8～4.7%，7.8～11.3% と良好な結果が得られた．各機関での検出限界は 0.001～0.025 μg/g であった．ETを添加したりんご及びなしの試験溶液ではLC/MS及びGC/MSによるマススペクトルの確認が可能であった．

Ethoxyquin

10.3358/shokueishi.43.366

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The Effects of Heavy Metals on the Microorganisms in River Water

Eisei kagaku (1979)

Toshihiro Nagayama Tsutao Kurechi

Oxygen uptake of the microorganisms cultured from river water were examined to find the effect of heavy metals with or without a substrate. Without the addition of a substrate, effect of a metal was examined in median toxic concentrations of oxygen uptake (TC50), and the metal toxicity decreased in the order of Hg2+, Cu2+, Ni2+, Cd2+, Zn2+, Al3+, Pb2+, Fe3+, Mn2+. When a substrate was added, the effect of metals appeared at a higher concentration. The modified Wiegand equation was applied to analyze the form of oxygen uptake inhibition caused by cadmium. The decrease of L and y0 values was indicated without substrate added, and when the substrate was added, to the effect of cadmium was different from the former. Dehydrogenase activity was related the decrease of oxygen uptake in the absence of a substrate.

10.1248/jhs1956.25.289

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Citations (2)

Determination of Alanycarb in Agricultural Products by HPLC

Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi) (1998)

Masako Ito Toshihiro Nagayama Maki Kobayashi Tsuneo Hashimoto Nahoko Haneishi

A simplified determination procedure for alanycarb in agricultural products by high performance liquid chromatography with a UV detector was developed.The homogenate of agricultural products was extracted with acetone. The crude extract was partitioned between 10% sodium chloride solution and ethyl acetate, and the ethyl acetate layer was evaporated to dryness. The residue was dissolved in n-hexane, and the solution was cleaned up on a Bond Elute® extraction cartridge PSA, then analyzed by liquid chromatography. Alanycarb was detected by measuring the absorbance at 230nm.Recoveries at the 0. 1ppm level were more than 70% from agricultural products except brown rice. Detection limits for the products were 0.01ppm in samples.

Cartridge

Residue (chemistry)

Absorbance

Hexane

Sodium acetate

10.3358/shokueishi.39.3_218

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Citations (2)

Methods of Analysis in Health Science : Qualitative and Quantitative Method for Trichothecene Mycotoxins and Zearalenone by LC/MS/MS or Histamine Measurement using the Enzymatic Method

The Pharmaceutical Society of Japan (2021)

Toshihiro Nagayama

Qualitative analysis

Source

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Decrease in Organic Solvent Extractable Ethion by Grapefruit Pectin during Processing

Journal of Agricultural and Food Chemistry (1997)

Toshihiro Nagayama

The effect of food components on pesticide residue was examined using citrus fruit often heated to make marmalade. Commercial grapefruit was peeled, and the parts were fractionated by extraction with several kinds of solvents (n-hexane, acetone, methanol, and water). The amount of organic solvent extractable ethion remaining after heating was smallest in the crude peel water extract. Purification of the water extract by deposition with methanol and dialysis produced a gel. The gel reduced the amount of several organophosphorus pesticides extracted by organic solvent during heating. From the IR spectra, the chief ingredient of the gel was considered to be pectin, which is contained in most plants. Thus, the pectin of grapefruit was considered to have masked organophosphorus pesticides from organic solvent extraction. Pectin is easily transuded from foodstuffs by cooking and appears to play a role in reducing the amount of pesticide extracted by organic solvents with heating. Keywords: Pesticide; food; component; effect; cooking

Ethion

Pectin

Residue (chemistry)

Ingredient

10.1021/jf9701401

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Citations (6)