气相色谱-质谱法测定生物检材中水胺硫膦

Determination of Isocarbophos in Bio-testing Materials by GC-MS

pH4．5生物检材溶液中的水胺硫膦用Oasis HLB 3cc固相萃取小柱分离，此小柱经离心干燥后用乙酸乙酯淋洗，所得洗出液吹氮浓缩至1mL供气相色谱-质谱法（GC-MS）分析用，对GGMS分析的条件进行了试验并给出了优化的分析参数。为了避免和减少样品的热分解，方法中采用了较高的柱前压，较高的载气流量以及较低的GC-MS间的接口温度。根据水胺硫膦标准的质谱图，确定了各主要强离子碎片的归属，并提出了水胺硫膦的标准谱库，作为水胺硫膦定性分析的基础。测定水胺硫膦的线性范围在0．05-100mg·L^-1之间，试验测得方法的平均回收率、相对标准偏差（n=5）及检出限（3S／N）依次为93．3％，2．5％及0．05mg·L^-1。

Isocarbophos in bio-testing materials was separated by SPE on Oasis HLB aPE column from sample solution buffered at pH 4. 5 with PBS. The SPE column was dried by centrifugation and eluted with ethylacetate to desorb isocarbophos from the column. The eluate was concentrated to 1 mL by N2-blowing and used for GC-MS analysis. Conditions for GC-MS analysis ware studied and the optimum parameters were given. Relatively high pre-column pressure, high flow-rate of carrying gas and low temperature at the connection inlet from GC to MS were adopted to reduce or avoid thermodecomposition of sample. Based on the mass spectrogram of standard isocarbopbos, the attribution of strong ion fragments were confirmed and standard spectrum database of isocarbophos was proposed, which is the basis of qualitative analysis of isocarbophos. Range of linearity found for determination of isoearbophos was between 0.05-100 mg·L^-1. Values of average recovery, RSD （n=5） and limit of detection （3S/N） were found to be 93.3%, 2. 5% and 0. 05 mg·L^-1 respectively.