Wilkes P S
J Assoc Off Anal Chem. 1981 Sep;64(5):1208-10.
A gas-liquid chromatography-mass spectrometric (GLC-MS) procedure is described for the confirmation of endosulfan I, endosulfan II, and endosulfan sulfate in apples and carrots. After extraction, cleanup, and determination by electron capture gas-liquid chromatography using current AOAC methodology, residues are confirmed by GLC-MS. The chemical ionization (CI) mode is used with methane as a reagent gas. Each residue is confirmed by a scan of only 4 regions of its mass spectrum rather than the full mass range. The 4 mass regions for the 2 endosulfan isomers are 274-280, 340-346, 368-374, and 404-412 atomic mass units (amu). For endosulfan sulfate, the mass regions are 286-294, 322-330, 384-392, and 420-428 amu. Four ions and their chlorine isotopic distributions are detected for each compound by this scanning technique. This method was developed by using carrots and apples to which had been added 0.1 ppm (50% of the current legal tolerance on carrots) of each of the 3 pesticides. The gas chromatographic retention times and the mass spectra of the 4 mass regions specified for the 3 pesticides were compared to those of reference standards injected under identical GLC-MS conditions and were used as the basis for confirming identity of the 3 compounds.
本文描述了一种气相色谱 - 质谱联用（GLC - MS）方法，用于确认苹果和胡萝卜中的硫丹I、硫丹II和硫丹硫酸酯。采用当前美国官方分析化学师协会（AOAC）的方法进行萃取、净化，并通过电子捕获气相色谱法进行测定，之后用GLC - MS对残留进行确认。化学电离（CI）模式以甲烷作为反应气。每种残留仅通过扫描其质谱的4个区域而非全质量范围来确认。两种硫丹异构体的4个质量区域分别为274 - 280、340 - 346、368 - 374和404 - 412原子质量单位（amu）。对于硫丹硫酸酯，质量区域为286 - 294、322 - 330、384 - 392和420 - 428 amu。通过这种扫描技术，每种化合物可检测到4个离子及其氯同位素分布。该方法是通过向胡萝卜和苹果中添加0.1 ppm（为胡萝卜当前法定耐受量的50%）的这3种农药中的每一种而开发的。将这3种农药指定的4个质量区域的气相色谱保留时间和质谱与在相同GLC - MS条件下注入的参考标准品进行比较，并以此作为确认这3种化合物身份的依据。
