Determination of airborne inorganic arsenic in workplaces by liquid chromatographyatomic fluorescence

  Objective  To establish a method for determination of As (Ⅲ) and As (Ⅴ) in the air of workplaces by liquid chromatography -atomic fluorescence spectrometry.

  Methods  The samples were extracted by 0.15 mol/L HNO₃ solution at 90℃ for 1 h, then As (Ⅲ) and As (V) were separated and analyzed with the mobile phase of 15 mmol/L diammonium hydrogen phosphate, using CNWSep AX(250 mm×4.0 mm×10 μm)(LAEQ-4025G7) column.

  Results  In the range of 0 -100 g/L, the linear correlation coefficients (r) of As (Ⅲ) and As (V)were 0.999 9 and 0.999 8, respectively. The detection limits of As (Ⅲ) and As (V) were 0.14 g/L and 0.38 g/L, and the elution efficiencies were 96.77% 98.66%, 96.77% 98.66% respectively. The recoveries of As (Ⅲ) and As (V) were 90.67% 95.60%, 91.82% 95.84%, and the relative standard deviations were 0.47% 1.44% and 0.48% 1.34% respectively.

  Conclusions  This pretreatment method can avoid morphological changes of inorganic arsenic species. The method has good separation effect on two inorganic arsenic species, and has high sensitivity and accuracy, and is suitable for the determination of inorganic arsenic in the air of workplaces.