Objective To develop an approach to determining ammonia in air by salicylate spectrophotometry.
Methods To collect air samples by large air-bubble absorption tube containing acidic solution; apply salicylate as chromogenic reagent and use 722N spectrophotometer in 690 nm wave-length to measure absorbency; determine the quantities of ammonia in air samples by colorimetric analysis.
Results The detection limit of this approach was 0.02 μg/mL; the relative standard deviations between inter-day precision and intra-day precision ranged between 0.5% to 2.1%; the spike recovery rates of samples ranged from 96.0% to 103.0%. The determined results of standard samples were within standard range. There were no significant differences between the results determined by salicylate spectrophotometry and GB method(Nessler's reagent method)(P>0.05).
Conclusion The approach to determining ammonia in air by salicylate spectrophotometry is easily operated and less interfered. Therefore, it can be easily selected and replicated at the grassroots level.
DownLoad: