Raina Renata, Sun Lina
Department of Chemistry and Biochemistry and Trace Analysis Facility (TAF), University of Regina, Regina, SK, Canada.
J Environ Sci Health B. 2008 May;43(4):323-32. doi: 10.1080/03601230801941667.
This paper describes a new analytical method for determination of organophosphorus pesticides (OPs) along with their degradation products involving liquid chromatography (LC) positive ion electrospray (ESI+) tandem mass spectrometry (MS-MS) with selective reaction monitoring (SRM). Chromatography was performed on a Gemini C6-Phenyl (150 mmx2.0 mm, 3 microm) with a gradient elution using water-methanol with 0.1% formic acid, 2 mM ammonium acetate mobile phase at a flow rate of 0.2 mL min(-1). The LC separation and MS/MS operating conditions were optimized with a total analysis time less than 40 minutes. Method detection limits of 0.1-5 microg L(-1) for selected organophosphorus pesticides (OP), OP oxon degradation products, and other degradation products: 3,5,6-trichloro-2-pyridinol (TCP); 2-isopropyl-6-methyl-4-pyrimidol (IMP); and diethyl phosphate (DEP). Some OPs such as fenchlorphos are less sensitive (MDL 30 microg L(-1)). Calibration curves were linear with coefficients of correlation better than 0.995. A three-point identification approach was adopted with area from first selective reaction monitoring (SRM) transition used for quantitative analysis, while a second SRM transition along with the ratio of areas obtained from the first to second transition are used for confirmation with sample tolerance established by the relative standard deviation of the ratio obtained from standards. This new method permitted the first known detection of OP oxon degradation products including chlorpyrifos oxon at Bratt's Lake, SK and diazinon oxon and malathion oxon at Abbotsford, BC in atmospheric samples. Atmospheric detection limits typically ranged from 0.2-10 pg m(-3).
本文介绍了一种用于测定有机磷农药（OPs）及其降解产物的新分析方法，该方法涉及液相色谱（LC）正离子电喷雾（ESI+）串联质谱（MS-MS）和选择性反应监测（SRM）。色谱分析在Gemini C6-苯基柱（150 mm×2.0 mm，3μm）上进行，采用梯度洗脱，流动相为含0.1%甲酸、2 mM醋酸铵的水-甲醇溶液，流速为0.2 mL min⁻¹。对LC分离和MS/MS操作条件进行了优化，总分析时间不到40分钟。选定的有机磷农药（OP）、OP氧磷降解产物及其他降解产物：3,5,6-三氯-2-吡啶醇（TCP）；2-异丙基-6-甲基-4-嘧啶醇（IMP）；以及磷酸二乙酯（DEP）的方法检测限为0.1 - 5μg L⁻¹。某些OPs如皮蝇磷的灵敏度较低（MDL为30μg L⁻¹）。校准曲线呈线性，相关系数优于0.995。采用三点鉴定方法，第一个选择性反应监测（SRM）转换的面积用于定量分析，而第二个SRM转换以及第一个与第二个转换所得面积之比用于确证，通过标准品所得比例的相对标准偏差确定样品容差。这种新方法首次在萨斯喀彻温省布拉茨湖的大气样品中检测到包括毒死蜱氧磷在内的OP氧磷降解产物，以及在不列颠哥伦比亚省阿伯茨福德的大气样品中检测到二嗪磷氧磷和马拉硫磷氧磷。大气检测限通常在0.2 - 10 pg m⁻³范围内。
