title: Enhanced sensitivity and resolution for the analysis of paralytic shellfish poisoning toxins in water using capillary electrophoresis with amperometric detection and field-amplified sample injection.
abstract: The profiling of the most lethal paralytic shellfish poisoning toxins (PSTs) in freshwater has increased the need to establish an alternative analytical method with high sensitivity and resolution. In this paper, a coupling technique of field-amplified sample injection (FASI) and CE with end-column amperometric detection (CE-AD) was developed to improve the detection sensitivity and separation of PSTs by electrokinetically injecting a water plug of analytes to the capillary filled with a high-conductivity BGE. Parameters affecting FASI and CE process were carefully adjusted to achieve the highest response and resolution. Separation selectivity for PSTs, especially for the analogues and epimers, was greatly enhanced by using 40 mM Britton-Robinson buffer (pH 9.5) as BGE, which altered the EOF and mobility of the analytes that interacted with polyborate ions. Satisfactory linear relationship between peak current and concentration of toxins were gained over a wide range of 1.95-254 μg/L. The detection limits (S/N = 3) for five PSTs ranged from 0.63 to 3.11 μg/L, which are below the health alert level in drinking water. In comparison with the up-to-date reporting chromatographic methods, the FASI-CE-AD method was simple, low-cost, selective, and sensitive enough for direct quantification of PSTs at very low levels, implying a potential for screening and monitoring of PSTs in surface waters.
authors: Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education & Fujian Province), College of Chemistry, Fuzhou University, Fuzhou, Fujian, P. R. China.
authors: Minsheng
authors: M
authors: Li
authors: Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education & Fujian Province), College of Chemistry, Fuzhou University, Fuzhou, Fujian, P. R. China.|Jinjiang Environmental Monitoring Centre, Jinjiang, Fujian, P. R. China.
authors: Xiaoyan
authors: X
authors: Chen
authors: Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education & Fujian Province), College of Chemistry, Fuzhou University, Fuzhou, Fujian, P. R. China.
authors: Yuan
authors: Y
authors: Guo
authors: Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education & Fujian Province), College of Chemistry, Fuzhou University, Fuzhou, Fujian, P. R. China.
authors: Bingyu
authors: B
authors: Zhang
authors: Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education & Fujian Province), College of Chemistry, Fuzhou University, Fuzhou, Fujian, P. R. China.
authors: Fengxiang
authors: F
authors: Tang
authors: Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education & Fujian Province), College of Chemistry, Fuzhou University, Fuzhou, Fujian, P. R. China.
authors: Xiaoping
authors: X
authors: Wu
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D057230:Limit of Detection; D016014:Linear Models; D008387:Marine Toxins / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D057096:Shellfish Poisoning
chemical_list: D008387:Marine Toxins
keywords: Capillary electrophoresis; End-cloumn amperometric detection; Field-amplified sample injection; Freshwater; Shellfish toxins