柱前衍生—液质联用法快速测定葡萄中单氰胺残留

建立了丹磺酰氯(DNS)柱前衍生—超高效液相色谱—串联质谱法(UPLC-MS/MS)测定葡萄中单氰胺的方法。样品经破壁机打碎,采用丙酮超声提取,在碱性条件下下与丹磺酰氯进行衍生反应。采用电喷雾(ESI)模式电离源负离子,多反应监测(MRM)模式进行检测,外标法定量。单氰胺在0. 000 1～0. 1 mg/kg范围内,峰面积与质量浓度之间线性关系良好,相关系数为0. 991。在0. 001、0. 01、0. 05、0. 1mg/kg 4档添加水平下,葡萄中单氰胺的平均回收率为79. 7%～92. 9%,精密度为3. 6%～7. 3%,定量限为0. 001mg/kg。该方法简便、快速、准确,完全满足葡萄样品中单氰胺的残留检测要求。

Determination of cyanamide residue in grapes by high performance liquid chromatography-tandem mass spectrometry coupled with precolumn derivatization

A method was established for the determination of cyanamide residues in grapes by ultra-high performance liquid chromatography-tandem mass spectrometric(UPLC-MS/MS)coupled with dansyl chloride(DNS)precolumn derivatization.The samples were homogenized,and then extracted with acetone under ultrasonication,and the extract was derivatized with dansylchloride under alkaline condition.The analysis of cyanamide was carried out under negative electrospray ionization(ESI-)mode and multiple reaction monitoring(MRM)mode,quantified by matrix matching curve external standard method.The results showed that the calibration curves of cyanamide were linear(r=0.991)in the concentration range of 0.0001~0.1 mg/kg.The average recoveries at four spiked levels of 0.001,0.01,0.05 and 0.1 mg/kg were in the ranges of 79.7%~92.9%,with relative standard deviations(RSDs)of 3.6%~7.3%.The limits of quantification(LOQS)of the analytes was 0.001 mg/kg.The method is simple,rapid and accurate,and was suitable for the confirmation and quantitative determination of cyanamide residues in grapes.