Sampling and analysis of airborne ammonia in workplaces of China.

Zhizhen Xu,Zhaohui Fu,Zhe Bi,Dongxu Wang,Ling Guo

doi:10.1002/1348-9585.12100

Abstract

ObjectivesWith the increasing demand for the detection of occupational hazard factors in workplaces, the national standard determination method for ammonia (sampling with absorbing solution‐analysis with Nessler reagent spectrophotometry) in the air of workplace presents many drawbacks during application in China. This review summarized the improvement and the alternate methods of the current sampling and analysis procedures for ammonia, aiming to provide reference to establish an appropriate method for the determination of ammonia in workplace air.MethodsScientific publications in English and Chinese and the standard methods of the Deutsche Forschungsgemeinschaft (DFG) in Germany, the National Institute for Occupational Safety and Health (NIOSH) and Occupational Safety and Health Administration (OSHA) in the United States, and Ministry of Health in China for airborne ammonia collection and analysis in the workplace were reviewed.ResultsThe measures to improve the current sampling and analysis procedures for ammonia in China were firstly summarized. For sampling, the decrease of absorbing solution concentration and the methanesulfonic acid solution as the alternate sampling solution were suggested. For analysis, the anti‐interference measures and the optimum reaction condition between ammonia and Nessler reagent were discussed. The alternate methods including sampling conducted using solid sorbent tubes and analysis performed by ion chromatography were then considered for the determination of ammonia.ConclusionsThe methods—sampling with acid‐treated solid sorbent tubes and analysis with ion chromatography—were more suitable for the determination of ammonia in workplace air. However, some details about ammonia sampling and analysis still need further investigation.

Highlights

Ammonia, with density of 0.771 g/L under standard conditions, is a colorless gas with strong irritating odor
The sampling efficiency of CH4O2S solution in the front midget-fritted glass bubbler could reach more than 95%, both for short and long-term sampling of ammonia, meeting the requirement (>90%) of the standard (GBZ/T 210.4-2008).[26,27,28]
The collection efficiency of the commercial acidtreated silica gel for ammonia could reach more than 98%, determined by ion chromatography or spectrophotometry

Summary

Introduction

With density of 0.771 g/L under standard conditions, is a colorless gas with strong irritating odor. It is usually used as refrigerant due to low boiling point. Personal exposure to ammonia at a certain concentration could cause a strong stimulating and corrosive effect on human eyes, nose, throat, and skin.[3,4] Exposure to ammonia at the concentration of about 20-95 mg/m3 in the urea fertilizer factory could induce acute respiratory symptoms and acute decline in lung function.[2] Chronic ammonia inhalation could cause pulmonary fibrosis and interstitial lung disease.[5]

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