气相色谱分析柑橘类水果中残留的苯丁锡

Determination of fenbutatin oxide residue in orange products by gas chromatography

建立了气相色谱-火焰光度检测器测定柑橘类水果中苯丁锡残留量的检测方法。样品在酸性条件下经丙酮及正己烷萃取并浓缩,用正己烷溶解残渣,经乙基溴化镁衍生后,采用硅胶固相萃取柱净化,正己烷-二氯甲烷(体积比为4∶1)混合液洗脱,用毛细管气相色谱-火焰光度检测器(锡滤光片:610nm)测定,外标法定量。结果表明:该方法的线性范围为0.2～2.0mg/L,相关系数r≥0.999 5;当阴性脐橙样品中加标水平为0.1～0.4mg/kg时,苯丁锡的回收率为79.6%～109.6%,相对标准偏差为3.60%～9.05%,方法的检出限为0.1mg/kg。该方法重复性好,灵敏度高,完全满足国内外柑橘类水果中苯丁锡残留分析的要求。

An analytical method for the determination of fenbutatin oxide （FBT） residue in oranges by capillary gas chromatography-flame photometric detection （GC-FPD） was developed. The FBT was extracted with acetone-acetic acid （99： 1, v/v） and hexane, filtered and evaporated by nitrogen evaporator in a water bath at 35℃. The residue was dissolved in hexane. The FBT in the solvent was derivatized with ethyl magnesium bromide for 15 min, 1 mol/L hydrochloride was added, the supernatant was collected and the solvent was evaporated to get dry supernatants, then the supernatant was dissolved in hexane and cleaned up with a silica solid phase extraction column, eluted with 5 mL hexane-dichloromethane （4： 1, v/v）, determined by GC. The standard curve was linear in the range of 0.2 - 2.0 mg/L. The correlation coefficients （r） were more than 0. 999 5, the average recoveries were 79.6% - 109.6% with the relative standard deviations （RSDs） of 3.60% -9.04% at the spiked levels of 0. 1 -0.4 mg/kg, and the detection limit of fenbutatin oxide was 0. 1 mg/kg. This method is suitable for the analysis of fenbutatin oxide residue in orange products.