超高效液相色谱-串联质谱法同时测定党参和当归中23种植物生长调节剂的残留量

Simultaneous Determination of Residues of 23Plant Growth Regulators in Codonopsis Radix and Angelica Sinensis by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry

样品经晾干、粉碎、过筛后,分取3.0 g,加入1.0%(体积分数)冰乙酸溶液5 mL,涡旋,使样品完全浸湿。浸泡30 min后加入乙腈15 mL,剧烈振摇10 min,加入无水硫酸镁(AMS)4.0 g和氯化钠1.0 g,剧烈摇散,防止盐结块,再剧烈振摇10 min,离心10 min。收集全部上清液,于40℃氮吹至近干,残渣用50%(体积分数)乙腈溶液1 mL复溶。所得溶液进入超高效液相色谱-串联质谱仪,其中的目标物在Waters AQUITY UPLC BEH Shield RP18色谱柱上用不同体积比的含5 mmol·L^(-1)甲酸铵的0.05%(体积分数,下同)甲酸溶液以及含5 mmol·L^(-1)甲酸铵和0.05%甲酸的乙腈溶液的混合溶液梯度洗脱分离,采用电喷雾离子源正(ESI+)、负(ESI-)离子模式电离,保留时间依赖多反应监测(sMRM)模式检测,基质匹配法定量。结果显示:23种植物生长调节剂的质量浓度均在一定范围内与对应的峰面积呈线性关系,测定下限(10S/N)为0.2~3.0μg·kg-1;按照标准加入法进行回收试验,回收率为75.2%~109%,测定值的相对标准偏差(n=5)为1.8%~13%;方法用于46批党参和30批当归样品的分析,其中有10.9%的党参样品和6.7%的当归样品中的4-硝基苯酚钠检出量超过了GB 2763-2021规定的限量(100μg·kg-1)。

After the sample was dried,crushed,and sieved,an aliquot(3.0g)was taken,and 5mL of 1.0%(volume fraction)glacial acetic acid solution was added to completely immerse the sample by vortex.After soaking for 30min,15mL of acetonitrile was added,and the mixture was shaken vigorously for 10min.Then 4.0g of anhydrous magnesium sulfate(AMS)and 1.0g of sodium chloride were added,and the mixture was shaken vigorously to prevent salt agglomeration,shaken vigorously for another 10min,and centrifuged for 10min.All the supernatant was collected,and blown to near dryness by nitrogen at 40℃,and the residue was dissolved in 1mL of 50%(volume fraction)acetonitrile solution.The obtained solution was introduced into the ultra-high performance liquid chromatograph-tandem mass spectrometer,and the targets were separated on the Waters AQUITY UPLC BEH Shield RP18chromatographic column by gradient elution with mixed solutions composed of 0.05%(volume fraction,the same below)formic acid solution containing 5mmol·L^(-1)ammonium formate and acetonitrile solution containing 5mmol·L^(-1)ammonium formate and 0.05%formic acid at different volume ratios,and ionized by the ESI+and ESI-modes,detected by the sMRM mode,and quantified by matrix matching method.It was shown that linear relationships between values of the mass concentration and the corresponding peak area of 23plant growth regulators were kept in definite ranges,with lower limits of determination(10S/N)in the range of 0.2-3.0μg·kg-1.Test for recovery was made according to the standard addition method,giving recoveries in the range of 75.2%-109%,and RSDs(n=5)of the determined values ranged from 1.8%to 13%.The proposed method was used for the analysis of 46batches of Codonopsis Radixand 30batches of Angelica sinensis samples.Among them,detection amounts of sodium 4-nitrophenol in 10.9%of Codonopsis Radixsamples and 6.7%of Angelica sinensis samples exceeded the limit(100μg·kg-1)specified in GB 2763-2021.