水杨酸盐分光光度法测定空气中的氨
Determination of Ammonia in Air by Salicylate Spectrophtometry
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摘要:
目的 探讨水杨酸盐分光光度法测定空气中氨的方法。 方法 用装有酸性溶液的大型气泡吸收管采集空气样品,以水杨酸盐为显色剂,采用722N型分光光度计,于波长690 nm处测定光密度比色定量。 结果 该方法的检出限为0.02 μg/mL,日间精密度和日内精密度的相对标准偏差为0.5%~2.1%,样品加标回收率在96.0%~103.0%之间。标准参考物质的测定值在标准值范围内,测定结果与国标法(纳氏试剂分光光度法)比较,差异无统计学意义(P>0.05)。 结论 空气中氨的水杨酸盐分光光度法操作简单,干扰少,具有良好的选择性和重现性,适合在基层推广应用。 Abstract: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.
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