title: [The optimization of 2-thiothiazolidine-4-carboxylic acid back extraction in urine and determination by HPLC].
abstract: OBJECTIVE
  Establishment of determination method of 2-thiothiazolidine-4-carboxylic acid (TTCA) in urine with HPLC.
  
  
  METHODS
  A volume of 0.5 ml hydrochloric acid (2 mol/L) and 0.5 ml pure water was added into 1 ml urine, and then extracted by 4 ml of diethyl ether by shaking for 2 min. Remove the water phase in a tube with plug and extract again, mix the two extraction diethyl ether together, take 4 ml by adding 2 ml borax-monopotassium phosphate buffer and shaking for 2 min to extract, then take the water phase to detect. A C(18) column and UV detector were used for separating and detecting. The wavelength was 273 nm, the flow rate was 1.0 ml/min, and the injection volume was 20 µl.
  
  
  RESULTS
  TTCA has a good linearity (r = 0.9995) over the concentration of1 1 ∼ 10 µg and the minimum detectable concentration of TTCA in urine was 0.1 µg/ml. The within-day precision (RSD) were 8.4%, 3.0% and 1.7%, the between-day precision (RSD) were 11%, 3.8%, 1.9%, respectively. The extraction recovery were between 80% ∼ 102%.
  
  
  CONCLUSIONS
  The method was accurate and sensitive to detect TTCA in urine.
authors.affiliation: Henan Provincial Institute of Occupational Health, Zhengzhou 450052, China.
authors.forename: Yan-yan
authors.initials: YY
authors.lastname: Lu
authors.forename: Qing-feng
authors.initials: QF
authors.lastname: Xiao
authors.forename: Kai-you
authors.initials: KY
authors.lastname: Jiang
authors.forename: Wen-hua
authors.initials: WH
authors.lastname: Qin
authors.forename: Shan-fa
authors.initials: SF
authors.lastname: Yu
mesh_terms: D002246:Carbon Disulfide / Q000652:urine*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D053778:Thiazolidines / Q000652:urine*
chemical_list: D053778:Thiazolidines; C031677:2-thioxo-4-thiazolidinecarboxylic acid; D002246:Carbon Disulfide