title: [Evaluation on the capability of testing carbon tetrachloride, benzene, methylbenzene, dimethylbenzene, p' p-DDT of the provincial centers for disease control and prevention].
abstract: OBJECTIVE
  To evaluate the Centers of Disease Control and Prevention's (CDC) provincial divisions' capabilities of detectingconcentrations of organic parameters such as carbon tetrachloride, benzene, methylbenzene, dimethylbenzene and pesticide parameter of p’ p-DDT in drinking water, by adopting a quality control assessment methodology of interlaboratory comparison.
  
  
  METHODS
  All laboratories had been divided into 2 groups, each of which contained aboutl6 laboratories. Organic concentrations and pesticide concentrations were assigned to 2 sample groups. Testing capabilities of the laboratories were evaluated through the use of robust statistical methods.
  
  
  RESULTS
  Thirty CDC provincial divisions, including municipalities under the central government and in autonomous regions, participated in this interlaboratory comparison. Twenty laboratories obtained positive results in all parameters, accounting for 66.7%. Eight laboratories' results were suspicious, accounting for 26.7%. Finally, 2 laboratories produced outliers, accounting for 6.7%.
  
  
  CONCLUSIONS
  The majority of provincial CDC participants in this interlaboratory comparison are capable of testing the concentrations of organic parameterssuch as carbon tetrachloride, benzene, and methylbenzene, dimethyl benzene, and pesticide concentrations of p' p-DDT in drinking water.
authors.forename: Jiaolan
authors.initials: J
authors.lastname: Yang
authors.forename: Ningtao
authors.initials: N
authors.lastname: Cao
authors.forename: Shiyao
authors.initials: S
authors.lastname: Li
authors.forename: Dongqing
authors.initials: D
authors.lastname: Chen
mesh_terms: D001554:Benzene / Q000032:analysis; D002251:Carbon Tetrachloride / Q000032:analysis; D002487:Centers for Disease Control and Prevention, U.S.; D003634:DDT / Q000032:analysis; D060766:Drinking Water / Q000032:analysis*; D006801:Humans; D007753:Laboratories / Q000592:standards*; D059021:Laboratory Proficiency Testing / Q000592:standards*; D010575:Pesticides; D014050:Toluene / Q000032:analysis; D014481:United States; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014992:Xylenes / Q000032:analysis
chemical_list: D060766:Drinking Water; D010575:Pesticides; D014874:Water Pollutants, Chemical; D014992:Xylenes; D014050:Toluene; D003634:DDT; D002251:Carbon Tetrachloride; D001554:Benzene