铜绿微囊藻中微囊藻毒素LR的UPLC-MS/MS法分析

Determination of Microcystin LR in Microcystis Aeruginosa by UPLC-MS/MS

为了实现对微囊藻细胞中微囊藻毒素LR(Microcystin LR)的准确定量,建立了铜绿微囊藻中微囊藻毒素LR的超高效液相色谱三重四级杆质谱联用(UPLC-MS/MS)分析方法。将铜绿微囊藻干藻粉复溶在50 m L 0.1%三氟乙酸水溶液中,-55℃/37℃反复冻融3次,HLB固相萃取小柱浓缩和净化。采用ACQUITY UPLC CSH^(TM)C_(18)色谱柱,以0.1%甲酸-水和0.1%甲酸-乙腈为流动相,梯度洗脱分离,UPLC-MS/MS外标法定量分析。微囊藻毒素LR在5 ng/m L^150 ng/m L范围内线性良好,相关系数大于0.995,方法检出限为0.28 ng/m L,加标回收率在98.5%~104%,日内重复性和日间重复性分别为3.5%和5.6%(n=6)。该方法操作简便,重复性好,对微囊藻细胞中微囊藻毒素MC-LR的定量准确可靠。

In order to quantify the amount of microcystin LR in the cell of Microcystis aeruginosa,an ultra- performance liquid chromatography tandem mass spectrometry（ UPLC- MS / MS） method was established. The dry powder of Microcystis aeruginosa was reconstituted in 50 m L water containing 0. 1% trifluoroacetic acid and extracted after repeated freezing and thawing at- 55℃ /37℃ for three times. The extract was concentrated and cleaned by HLB SPE cartridge. The chromatographic separation was performed on ACQUITY UPLC CSHTMC_（18） column with gradient elution of water（ containing 0. 1% formic acid）- acetonitrile（ containing 0. 1% formic acid）. Quantitative analysis was performed by UPLC- ESI- MS / MS with external standard method. The method showed good linear correlation in arrange of 5 ng / m L ~ 150 ng / m L with correlation coefficient greater than 0. 995. The limit of detection for MC- LR was 0. 28 ng / m L. The recovery was between 98. 5% and 114%. The intra- and inter day precisions were 3. 5%and 5. 6%（ n = 6）,respectively. The method is simple and with good repeatability and can quantify the amount of MC- LR in Microcystis cell accurately.