A method was developed for the quantitative determination of cyanamide in grapes and cherries by liquid chromatography-tandem mass spectrometry(LC-MS/MS)coupled with dansyl chloride(DNS)precolumn derivatization. First,the samples were homogenized,and then extracted with ethyl acetate under ultrasonication. The water was removed using anhy-drous sodium sulfate,and the extract was concentrated and derivatized with dansyl chloride under alkaline condition. The separation was performed on a Shimadzu Shim-pack XR-ODS col-umn(75 mm×2.0 mm,1.6 μm)with the mobile phases of methanol and 2 mmol/L ammonium acetate aqueous solution(containing 0.05%(v/v)formic acid)in a gradient elution mode. The identification and quantification of cyanamide were carried out by MS/MS in positive electros-pray ionization(ESI+)and multiple reaction monitoring(MRM)mode. The calibration curves showed good linearities in the range of 0.01-1.0 mg/L with the correlation coefficients not less than 0.999 0. The average recoveries of cyanamide spiked at 0.01,0.05 and 1.0 mg/kg in cher-ries and grapes were between 75% and 81%,and the relative standard deviations(RSDs)were between 6.5% and 9.8%. Both the limits of quantification(LOQs)of the analytes were 0.01 mg/kg. The method is simple,rapid,accurate and suitable for the confirmation and quantifica-tion of cyanamide in cherries and grapes.%建立了丹磺酰氯(DNS)柱前衍生-液相色谱-串联质谱(LC-MS/MS)测定葡萄和樱桃中单氰胺的方法.样品经破壁机匀浆,乙酸乙酯超声提取,无水硫酸钠除水,提取液经减压浓缩,在碱性条件下与丹磺酰氯进行衍生反应.色谱柱为岛津 Shim-pack XR-ODS色谱柱(75 mm×2.0 mm,1.6 μm),流动相为甲醇和含0.05%(体积分数)甲酸的2 mmol/L醋酸铵水溶液,梯度洗脱,采用电喷雾离子源正离子多反应监测模式进行质谱检测.单氰胺在0.01~1.0 mg/L范围内,峰面积与质量浓度之间线性关系良好,相关系数不小于0.9990.在0.01、0.05和1.0 mg/kg的添加水平下,葡萄和樱桃中单氰胺的平均回收率为75%~81%,精密度为6.5%~9.8%,定量限为0.01 mg/kg.该方法简便、快速、可靠,可用于批量检测葡萄和樱桃中单氰胺残留.
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