气相色谱分析柑橘类水果中残留的苯丁锡

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: 610 nm)测定,外标法定量。结果表明: 该方法的线性范围为0.2～2.0 mg/L,相关系数r≥0.9995;当阴性脐橙样品中加标水平为0.1～0.4 mg/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0.1 mg/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。

Determination of fenbutatin oxide residue in orange products by gas chromatography

An analytical method for the determination of fenbutatin oxide ( FBT) residue in oranges by capillary gas chromatography-flame photometric detection ( GC-FPD) was devel-oped. 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 hex-ane. 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), deter-mined 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 anal-ysis of fenbutatin oxide residue in orange products.