Núñez Oscar, Moyano Encarnación, Galceran Maria Teresa
Departament de Química Analítica, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, E-08028 Barcelona, Spain.
J Chromatogr A. 2002 Oct 18;974(1-2):243-55. doi: 10.1016/s0021-9673(02)00906-8.
Conditions for the simultaneous determination of the three herbicides paraquat, diquat and difenzoquat and the two plant growth regulators chlormequat and mepiquat by pressure-assisted capillary electrophoresis coupled to mass spectrometry (ion-trap) using electrospray as ionisation source have been established. A 200 mM formic acid-ammonium formate buffer solution at pH 3.0 with 50% of methanol was used as carrier electrolyte. Some capillary electrophoresis-mass spectrometry parameters such as sheath liquid and sheath gas flow-rates, sheath liquid composition, electrospray voltage andthe CE capillary position were optimised. The MS and MS-MS spectra of positive ions were studied in order to obtain structural information for the confirmation of the identity. The use of labelled standards allowed to confirm fragment ions assignation. The detection limits, based on a signal-to-noise ratio of 3:1, were between 0.5 and 2.5 mg l(-1) with hydrodynamic injection (10 s) and between 1 and 10 microg l(-1) with elecrokinetic injection (20 s, 10 kV) using standards in ultrapure water. Quality parameters such as linearity and run-to-run precision (n=6) were established. Quantitation was carried out using labelled standards. The method has been applied to the analysis of contaminated irrigation water and spiked mineral water samples.
已建立了使用电喷雾作为电离源的压力辅助毛细管电泳-质谱联用（离子阱）同时测定三种除草剂百草枯、敌草快和地芬诺喹以及两种植物生长调节剂矮壮素和甲哌鎓的条件。使用pH 3.0的200 mM甲酸-甲酸铵缓冲溶液与50%的甲醇作为载体电解质。对一些毛细管电泳-质谱参数，如鞘液和鞘气流量、鞘液组成、电喷雾电压和CE毛细管位置进行了优化。研究了正离子的质谱和串联质谱，以获取用于确认身份的结构信息。使用标记标准品可确认碎片离子的归属。基于3:1的信噪比，采用流体动力进样（10 s）时检测限在0.5至2.5 mg l⁻¹之间，采用电动进样（20 s，10 kV）时检测限在1至10 μg l⁻¹之间，使用超纯水中的标准品。建立了诸如线性和批间精密度（n = 6）等质量参数。使用标记标准品进行定量。该方法已应用于受污染灌溉水和加标矿泉水样品的分析。
