水产品中硫氰酸盐的气相色谱-质谱测定方法研究

Determination of Thiocyanate in Aquatic products by Gas Chromatography-Mass Spectrometry

建立利用气相色谱-质谱法(GC-MS)测定水产品中硫氰酸盐的检测方法。样品加水超声提取,加α-溴-2,3,4,5,6-五氟甲苯(PFB.Br)和十六烷基三甲基溴化铵(CTAB)进行衍生化反应,高速冷冻离心,衍生产物用气相色谱-质谱进行分析,采用选择离子扫描方式,外标法定量。在0.025~0.50 mg· kg^-1范围内线性关系良好,相关系数大于0.99。通过优化前处理和上机条件,方法定量限(S/N≥10)为 0.025mg· kg^-1,在样品中进行0.10mg· kg^-1、0.25mg· kg^-1和0.50mg· kg^-1加标水平测试,其回收率为70.6~88.2%,RSD为3.6~10.4%。本文建立的水产品中硫氰酸盐测定方法快速、简便、可靠,可用于水产品样品中硫氰酸盐的测定。

A method for the determination of thiocyanate in aquatic products was developed by gas chromatography-mass spectrometry( GC-MS). The sample was extracted with water and ultrasonic extraction,followed by the derivatization reac tion of alpha bromo-2,3,4,5,6-pentafluorotoluene(PFB.Br) and hexadecyl trimethyl ammonium bromide( CTAB).The derivative products were analyzed by gas chromatography-mass spectrometry. Determinations were performed with selected ion monitoring(SIM) mode and external standard method was adopted in the quantification. The linear relationship was good in the range of 0.025 mg· kg^-1 to 0.50 mg kg-1,and the correlation coefficient was greater than 0.99. By optimizing the pretreatment and machine conditions,the lower limit of quantitation( S/N≥10) of the method was 0.025 mg· kg^-1. Tests for recovery were made by addition of standards of 0.10 mg· kg^-1,0.25 mg· kg^-1 and 0.50 mg· kg^-1 in samples,the recoveries of the pesticide were in the range of 70.6 ~ 88.2 %,the relative standard deviations were 3.6 ~ 10.4 %.The method established in this paper is rapid,simple and reliable,and can be used for the determination of thiocyanate in aquatic products.