有机氯农药多残留GC-MS分析方法研究

Study on the Analytical method for Organochlorine Pesticide Residue Using Gas Chromatography Mass Spectrometry

应用Ｍａｓｌａｂ的定量软件，以选择离子扫描方式，建立了有机氯农药多残留的ＧＣ－ＭＳ定量测定方法。经方法的线性试验、精密度试验、检测限试验，验证了有机氯农药多残留ＧＣ－ＭＳ分析方法的可行性。ＰＣＮＢ和ｐｐ＇－ＤＤＴ在０．００２５～０．５０ｎｇ，α－ＨＣＨ、β－ＨＣＨ、γ－ＨＣＨ、δ－ＨＣＨ、ｏｐ＇－ＤＤＴ、ｐｐ＇－ＤＤＤ、ｐｐ＇－ＤＤＥ、ＨＣＢ在０．００２０～０．４０ｎｇ范围内呈现良好的线性关系；方法的最低检出量：ＰＣＮＢ和ｐｐ＇－ＤＤＴ为０．００２５ｎｇ，α－ＨＣＨ、β－ＨＣＨ、γ－ＨＣＨ、δ－ＨＣＨ、ｏｐ＇－ＤＤＴ、ｐｐ＇－ＤＤＤ、ｐｐ＇－ＤＤＥ、ＨＣＢ为０．００２０ｎｇ．

A gas chromatographic electron ionization-mass spectrometric method(GC EIMS) was developed for determining organochlorine pesticide residues. Ten organochlorine pesticides including alpha, beta, gamma and delta isomers of hexachlorocyclohexane(HCH), pp' DDE, pp' DDT,op' DDT,pp' DDT,pentachloronitrobenzene (Quintozene, PCNB) and hexachlorobenzene(HCB) were determined respectively. Targeted pesticide analyses were separated on DB 5 capillary column. The optimum chromatographic conditions and MS parameter were determined. In test condition, each constituent in the standard mixture was separated efficiently. The retention time of each compound and its characteristic ion were determined in fullscan mode from 50 to 450 amu. The values of their mass spectrum on the total ion current(TIC) with fullscan mode agree with those of NIST and pesticide libraries. The characteristic ions were selected to quantify at m/z 181 for the isomers of HCH, m/z 284 for HCB, m/z 295 for PCNB, m/z 246 for pp' DDE, m/z 235 for pp' DDD, op' DDT and pp' DDT. The accuracy and reliability were proved respectively by linear test, precise test and recovery test. The linear ranges of PCNB and pp' DDT are 0 0025～0 50 μg/ml. The ranges of the isomers of HCH, pp' DDE, pp' DDD and op' DDT are 0 0020～0 40 μg/ml. The limits of detection are 0 0025ng for PCNB and pp' DDE, but 0 0020ng for the isomers of HCH,HCB, pp' DDE, pp' DDD and op' DDT.