Improvement of sample pretreatment for measurement of airborne tin and its compounds by use of AAS

Objective To seek improvements of the sample pretreatment of current method GBZ/T 160.22-2004 for determination of tin and its compounds in the air of workplace so as to establish a method of higher efficiency and accuracy. Methods The tin content on the filter membranes was determined respectively by the current method GBZ/T 160.22-2004 as well as the improved method with new sample pretreatment procedures. Filter membrane was digested in a covered-tube within 1.0 mL concentrated hydrochloric acid in water bath of approximate 50℃. Results The recovery rate of the current method GBZ/T 160.22-2004 was below 50.0% while that of the improved one was over 99.0%. Conclusion The improved method with new sample pretreatment procedure is more convenient for operation and receives higher recovery, Furthermore, this new pretreatment procedure reduces the harm both to lab operators and to the environment.