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    题名: Determination of melamine and cyanuric acid in powdered milk using injection-port derivatization and gas chromatography-tandem mass spectrometry with furan chemical ionization
    作者: Tzing,SH;Ding,WH
    贡献者: 化學學系
    关键词: VOLUME ONLINE DERIVATIZATION;NONYLPHENOL POLYETHOXYLATES;LIQUID-CHROMATOGRAPHY;DEGRADATION-PRODUCTS;RESIDUES;WATERS
    日期: 2010
    上传时间: 2012-03-27 18:07:57 (UTC+8)
    出版者: 國立中央大學
    摘要: A reliable, sensitive and eco-friendly injection-port trimethylsilylated (TMS) derivatization and gas chromatography-tandem mass spectrometry (GC-MS/MS) with furan chemical ionization (furan-CI) method was developed to determine melamine and cyanuric acid in powdered milk samples. The effects of several parameters related to the TMS-derivatization process (i.e., injection-port temperature, residence time and volume of silylating agent) and of various Cl agents were investigated. Addition of a solution (3 mu L) of bis(trimethyl)silyltrifluoroacetamide (BSTFA) containing 1% trimethylchlorosilane (TMCS) reagent to a 20-mu L extract from the powdered milk sample gave an excellent yield of the tris-TMS-derivatives of melamine and cyanuric acid at an injection-port temperature of 90 degrees C. Furthermore, using furan as the Cl agent in conjunction with tandem mass spectrometry provided the greatest sensitivity and selectivity of detection. The limits of quantitation (LOQs) for melamine and cyanuric acid were 0.5 and 1.0 ng/g in 0.5-g of powdered milk samples, respectively. The recoveries from spiked samples - after simple ultra-sonication with 5% dimethyl sulfoxide in acetonitrile coupled with n-hexane liquid-liquid extraction - ranged from 72% to 93% with relative standard deviations of lower than or equal to 18%. In three of four real powdered milk samples, melamine was detected at concentrations ranging from 36 to 1460 ng/g; and cyanuric acid was detected in two of these samples at concentrations of 17 and 180 ng/g. (C) 2010 Elsevier B.V. All rights reserved.
    關聯: JOURNAL OF CHROMATOGRAPHY A
    显示于类别:[化學學系] 期刊論文

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