Abstract:Objective To improve the method to determine phosphoric acid in workplace air, then we can enhance the sensitivity and accuracy of the method. Methods Phosphoric acid in workplace air was sampled with filter film of super thin glass fiber of 0.4μm and applied the improved method for testing, the credibility of the method was valuated by detection limit, precision and recovery. Results There was a good linearity within the concentration of 1.00~100.0μg with the correlation coefficient of 0.9998~0.9999. The detection limit of this approach was 0.078μg/mL and the lowest concentration of quantification was 0.0010mg/m3(sampling volume was 75L). The precision was 1.58%~7.91%, the recovery was 91.50%~95.37%. Conclusion The improved approach is simple, and it has good sensitivity and accuracy, which was superior to GB method.