title: Combination of micelle collapse and field-amplified sample stacking in capillary electrophoresis for determination of trimethoprim and sulfamethoxazole in animal-originated foodstuffs.
abstract: An on-line preconcentration method combining micelle to solvent stacking (MSS) with field-amplified sample stacking (FASS) was employed for the analysis of trimethoprim (TMP) and sulfamethoxazole (SMZ) by capillary zone electrophoresis (CZE). The optimized experimental conditions were as followings: (1) sample matrix, 10.0mM SDS-5% (v/v) methanol; (2) trapping solution (TS), 35mM H3PO4-60% acetonitrile (CH3CN); (3) running buffer, 30mM Na2HPO4(pH=7.3); (4) sample solution volume, 168nL; TS volume, 168nL; and (5) 9kV voltage, 214nm UV detection. Under the optimized conditions, the limits of detection (LODs) for SMZ and TMP were 7.7 and 8.5ng/mL, and they were 301 and 329 times better compared to a typical injection, respectively. The contents of TMP and SMZ in animal foodstuffs such as dairy products, eggs and honey were analyzed, too. Recoveries of 80-104% were acquired with relative standard deviations of 0.5-5.4%.
authors.affiliation: Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China. Electronic address: lhliu02@126.com.
authors.forename: Lihong
authors.initials: L
authors.lastname: Liu
authors.affiliation: Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wan
authors.affiliation: Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Ecology, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
authors.forename: Shunshan
authors.initials: S
authors.lastname: Duan
authors.affiliation: Laboratory Medicine Center, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, China.
authors.forename: Chunli
authors.initials: C
authors.lastname: Yang
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D005502:Food; D008823:Micelles; D013420:Sulfamethoxazole / Q000737:chemistry*; D014295:Trimethoprim / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D008823:Micelles; D014295:Trimethoprim; D013420:Sulfamethoxazole
keywords: Acetonitrile (PubChem CID: 6342); Animal-originated foodstuffs; Disodium hydrogen phosphate dodecahydrate (PubChem CID: 24203); Ethanol (PubChem CID: 702); Ethyl acetate (PubChem CID: 8857); Field-amplified sample stacking; Methanol (PubChem CID: 887); Micelle to solvent stacking; Phosphoric acid (PubChem CID: 1004); Sodium dodecyl sulfate (PubChem CID: 3423265); Sodium hydroxide (PubChem CID: 14798); Sodium sulfate anhydrous (PubChem CID: 24436); Sulfamethoxazole; Sulfamethoxazole (PubChem CID: 5329); Trimethoprim; Trimethoprim (PubChem CID: 5578)