title: [Analysis of the results and methods on proficiency testing of determination of Fe, Mn in drinking water].
abstract: OBJECTIVE
  To analyse the results and methods on proficiency testing(PT) for determination of Fe, Mn in drinking water and to discuss the influencing factors. With a view to the laboratory for accurate determination of drinking water iron and manganese to provide technical support.
  
  
  METHODS
  180 labs from 30 provinces (cities), autonomous regions took part in the PT. Based on methods of PT, statistical analysis of the results, to find the causes of dissatisfactory results.
  
  
  RESULTS
  According to the results of the report for the first time, the PT showed that 85.56% labs presented satisfactory results of determination of Fe and 87.71% labs presented satisfactory results of determination of Mn. In addition to ICP/MS, it showed that 76.00%, 88.89%, 93.75% respectively presented satisfactory results of the methods of AAS, ICP-AES and chemical of determination of Fe. It showed that 79.23%, 94.29%, 72.73% respectively presented satisfactory results of the methods of chemical, AAS and ICP-AES of determination of Mn. The initial results of 37 labs had dissatisfactory. Results of statistics showed that iron, manganese at the same time [ZB] > or = 3 for the 11 labs.
  
  
  CONCLUSIONS
  Most of the labs that took part in the PT have good competence in analyzing Fe, Mn. The main reasons of the dissatisfactory results were larger systematic errors, experimental blank, matrix interference and feeble control ability of the key point of the experiment.
authors: Center for Disease Prevention and Control, Beijing 100013, China.
authors: Peiyao
authors: P
authors: Tian
authors: Xinhua
authors: X
authors: Xiang
authors: Sujuan
authors: S
authors: Zhao
authors: Yan
authors: Y
authors: Sun
authors: Xiaoqun
authors: X
authors: Mu
authors: Xiong
authors: X
authors: He
mesh_terms: D002681:China; D060766:Drinking Water / Q000032:analysis*; D007501:Iron / Q000032:analysis*; D059021:Laboratory Proficiency Testing / Q000706:statistics & numerical data*; D008345:Manganese / Q000032:analysis*; D011786:Quality Control
chemical_list: D060766:Drinking Water; D008345:Manganese; D007501:Iron