Determination and Identification of Daminozide in Fresh Fruits Purchased in Japan

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YUMIKO NAKAMURA*, YUKARI HASEGAWA, YASUHIDE TONOGAI, and YOSHIO ITO

Division of Food Chemistry, National Institute of Hygienic Sciences, Osaka Branch, 1-1-43, Hoenzaka, Chuo-ku, Osaka, 540, Japan

(Received for publication December 4, 1989) Downloaded from http://meridian.allenpress.com/jfp/article-pdf/53/8/689/1661423/0362-028x-53_8_689.pdf by guest on 01 October 2021

ABSTRACT noamminferroate (TPF) was purchased from Tokyo Kasei Kogyo Co., Ltd. Other reagents were of the guaranteed grade. The concentration of residual daminozide (trade name of Stock solutions of daminozide and UDMH containing 1 formulation: Alar or B-Nine) in cherries, grapes, peaches, and mg/ml were prepared in distilled water. Working standards of apples purchased in Japan was investigated using the colorimet- UDMH containing 1-100 u.g/ml were prepared by dilution of the ric method. Daminozide hydrolyzes in boiling strong alkaline stock solution in distilled water. solution to release unsymmetrical dimethylhydrazine which is Ten percent sodium hydroxide solution, 10% oxalic acid distilled and reacted with trisodium pentacyanoamine ferroate to solution, and 0.1% TPF reagent were prepared by dissolving in form a specific red color at pH 4.5. This color is measured water, respectively. Phenolphthalein indicator (concentration of spectrophotometrically. The levels of daminozide detected were 1%) was prepared by dissolving in ethanol. 0.07-1.39 ppm in cherries (11 samples), 0-0.36 ppm in grapes Two g of N-methyl-N-nitrosourea was dissolved in 20 ml (10 samples), 0-0.42 ppm in peaches (9 samples), and 0-0.88 of diethylether, and 20% NaOH solution was added dropwise to ppm in apples (10 samples). Furthermore, daminozide in each yield yellowish diazomethane reagent. sample was identified as methyl daminozide by the gas chroma- Cherries, grapes, peaches, and apples were purchased from tography/mass spectrometry (GC/MS) method. the shops in Osaka Prefecture in July or August, 1989. They were immediately refrigerated and stocked at -20°C until ana lyzed the residual daminozide concentrations. Daminozide (succinic acid 2'-2'-dimethylhydrazide; trade name of formulation: Alar or B-Nine) is a plant growth Apparatus regulator used in fruit and flower culture (/). Degradation Steam distillation apparatus was used for the determination of the parent compound in the fruits as well as in mam of daminozide. Hitachi 556 double wavelength double beam mals may, under certain conditions, yield 1,1-dimethylhy spectrophotometer was used for the determination of daminozide drazine (unsymmetrical dimethylhydrazine, UDMH) (1). by a colorimetric method. In November 26, 1973, the Japanese Environmental A double focusing mass spectrometer with a gas chromato- Agency imposed the tolerance of residual daminozide in graph and a high speed data aquisition system (JEOL JMS- cherries, grapes, peaches and apples to be 25 ppm (2). DX302+JMA-DA5000) was used for the identification of dami Daminozide has been implicated in the production of nozide in fruits by GC/MS method. tumors in mice (3,4) and rats (4,5). UDMH has also been shown to be a carcinogen in mice (6). Determination of daminozide by colorimetric method Therefore, daminozide has been considered hazard Residual concentration of daminozide was determined by ous; the Japanese government required a survey of dami the Japanese official method (7) revised by Environmental Agency nozide residue in foods. We did for the first-time survey in 1987 with a little modification. This method is similar as the the residual daminozide concentration in domestic and official U.S. Environmental Protection Agency (EPA) method imported cherries, grape