Spectrophotometry and gas phase molecular absorption spectrometry for determination of nitrite nitrogen in flue gas were compared.KOH absorption solution was used to absorb nitrite nitrogen in flue gas,and the concent...Spectrophotometry and gas phase molecular absorption spectrometry for determination of nitrite nitrogen in flue gas were compared.KOH absorption solution was used to absorb nitrite nitrogen in flue gas,and the concentration of nitrite nitrogen in the absorption solution was determined by spectrophotometry and gas phase molecular absorption spectrometry to obtain the concentration of nitrite nitrogen in flue gas.The experiments show that both methods are accurate and reliable.展开更多
Nessler's reagent spectrophotometry,gas phase molecular absorption spectrometry and ion chromatography were respectively used to determine ammonia nitrogen in surface water.The detection limit,precision,accuracy a...Nessler's reagent spectrophotometry,gas phase molecular absorption spectrometry and ion chromatography were respectively used to determine ammonia nitrogen in surface water.The detection limit,precision,accuracy and recovery rate of the three methods were compared,and the determination results of the actual water samples were analyzed by t test.The results showed that the three methods all could meet the requirement of the laboratory quality control,and there was no significant difference in the determination results.Compared with Nessler's reagent spectrophotometry,the operation of gas phase molecular absorption spectrometry and ion chromatography operation was more convenient and fast and has no pollution,which can be used for the determination of ammonia nitrogen content in a large quantity of surface water samples.展开更多
As more attention is being paid to the characteristics of atmospheric amines,there is also an increasing demand for reliable detection technologies.Herein,a method was developed for simultaneous detection of atmospher...As more attention is being paid to the characteristics of atmospheric amines,there is also an increasing demand for reliable detection technologies.Herein,a method was developed for simultaneous detection of atmospheric amines in both gaseous and particulate phases using gas chromatography-mass spectrometry(GC-MS).The amine samples were collected with and without phosphoric acid filters,followed by derivatization with benzenesulfonyl chloride under alkaline condition prior to GC-MS analysis.Furthermore,the method was optimized and validated for determining 14 standard amines.The detection limits ranged from0.0408-0.421μg/mL(for gaseous samples)and 0.163-1.69μg/mL(for particulate samples),respectively.The obtained recoveries ranged from 68.8%-180%and the relative standard deviation was less than 30%,indicating high precision and good reliability of the method.Seven amines were simultaneously detected in gaseous and particulate samples in an industrial park using the developed method successfully.Methylamine,dimethylamine and diethylamine together accounted for 76.7%and 75.6%of particulate and gaseous samples,respectively.By comparing the measured and predicted values of gas-particle partition fractions,it was found that absorption process of aqueous phase played a more important role in the gas-partition of amines than physical adsorption.Moreover,the reaction between unprotonated amines and acid(aq.)in water phase likely promoted water absorption.Higher measured partition fraction of dibutylamine was likely due to the reaction with gaseous HCl.The developed method would help provide a deeper understanding of gas-particle partitioning as well as atmospheric evolution of amines.展开更多
文摘Spectrophotometry and gas phase molecular absorption spectrometry for determination of nitrite nitrogen in flue gas were compared.KOH absorption solution was used to absorb nitrite nitrogen in flue gas,and the concentration of nitrite nitrogen in the absorption solution was determined by spectrophotometry and gas phase molecular absorption spectrometry to obtain the concentration of nitrite nitrogen in flue gas.The experiments show that both methods are accurate and reliable.
文摘Nessler's reagent spectrophotometry,gas phase molecular absorption spectrometry and ion chromatography were respectively used to determine ammonia nitrogen in surface water.The detection limit,precision,accuracy and recovery rate of the three methods were compared,and the determination results of the actual water samples were analyzed by t test.The results showed that the three methods all could meet the requirement of the laboratory quality control,and there was no significant difference in the determination results.Compared with Nessler's reagent spectrophotometry,the operation of gas phase molecular absorption spectrometry and ion chromatography operation was more convenient and fast and has no pollution,which can be used for the determination of ammonia nitrogen content in a large quantity of surface water samples.
基金supported from the National Natural Science Foundation of China(Nos.42020104001 and 41805103)Local Innovative and Research Team Project of Guangdong Pearl River Talents Program(No.2017BT01Z032)the Fund from Chemistry and Chemical Engineering Guangdong Laboratory(No.1922009)
文摘As more attention is being paid to the characteristics of atmospheric amines,there is also an increasing demand for reliable detection technologies.Herein,a method was developed for simultaneous detection of atmospheric amines in both gaseous and particulate phases using gas chromatography-mass spectrometry(GC-MS).The amine samples were collected with and without phosphoric acid filters,followed by derivatization with benzenesulfonyl chloride under alkaline condition prior to GC-MS analysis.Furthermore,the method was optimized and validated for determining 14 standard amines.The detection limits ranged from0.0408-0.421μg/mL(for gaseous samples)and 0.163-1.69μg/mL(for particulate samples),respectively.The obtained recoveries ranged from 68.8%-180%and the relative standard deviation was less than 30%,indicating high precision and good reliability of the method.Seven amines were simultaneously detected in gaseous and particulate samples in an industrial park using the developed method successfully.Methylamine,dimethylamine and diethylamine together accounted for 76.7%and 75.6%of particulate and gaseous samples,respectively.By comparing the measured and predicted values of gas-particle partition fractions,it was found that absorption process of aqueous phase played a more important role in the gas-partition of amines than physical adsorption.Moreover,the reaction between unprotonated amines and acid(aq.)in water phase likely promoted water absorption.Higher measured partition fraction of dibutylamine was likely due to the reaction with gaseous HCl.The developed method would help provide a deeper understanding of gas-particle partitioning as well as atmospheric evolution of amines.
