title: [Evaluation of uncertainty for determination of tin and its compounds in air of workplace by flame atomic absorption spectrometry].
abstract: OBJECTIVE
  To investigate the method for uncertainty evaluation of determination of tin and its compounds in the air of workplace by flame atomic absorption spectrometry.
  
  
  METHODS
  The national occupational health standards, GBZ/T160.28-2004 and JJF1059-1999, were used to build a mathematical model of determination of tin and its compounds in the air of workplace and to calculate the components of uncertainty.
  
  
  RESULTS
  In determination of tin and its compounds in the air of workplace using flame atomic absorption spectrometry, the uncertainty for the concentration of the standard solution, atomic absorption spectrophotometer, sample digestion, parallel determination, least square fitting of the calibration curve, and sample collection was 0.436%, 0.13%, 1.07%, 1.65%, 3.05%, and 2.89%, respectively. The combined uncertainty was 9.3%.The concentration of tin in the test sample was 0.132 mg/m³, and the expanded uncertainty for the measurement was 0.012 mg/m³ (K=2).
  
  
  CONCLUSIONS
  The dominant uncertainty for determination of tin and its compounds in the air of workplace comes from least squares fitting of the calibration curve and sample collection. Quality control should be improved in the process of calibration curve fitting and sample collection.
authors.affiliation: Ningxia Centers for Disease Control and Prevention, Ningxia 750004, China.
authors.forename: Qiuning
authors.initials: Q
authors.lastname: Wei
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wei
authors.forename: Fangfang
authors.initials: F
authors.lastname: Liu
authors.forename: Yalei
authors.initials: Y
authors.lastname: Ding
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis*; D008962:Models, Theoretical; D013054:Spectrophotometry, Atomic; D014001:Tin / Q000032:analysis*; D035501:Uncertainty; D017132:Workplace
chemical_list: D000395:Air Pollutants, Occupational; D014001:Tin