| Ethylamine,isopropylamine,and n-butylamine are important chemical raw materials for the production of pesticides,dyes,medicines,pesticides,emulsifiers,and surfactants.Workers in the workplace may come into contact with ethylamine,isopropylamine and n-butylamine through the respiratory tract and skin.They are highly irritating to the eyes,upper respiratory tract,lungs,skin,etc.,and can cause coughing,dyspnea,chest pain,bronchitis,and chemicals.Pneumonia,pulmonary edema,and even coma can damage the cornea,cause burns and even blindness.my country's "Occupational Exposure Limits for Hazardous Factors in the Workplace Part 1 Chemical Hazardous Factors"(GBZ-2.1)stipulates that the maximum allowable concentration(MAC)of n-butylamine is 15mg/m3,and the time-weighted average allowable concentration of ethylamine(PC-TWA)is 9mg/m3,short-term exposure tolerance(PC-STEL)is 18 mg/m3,isopropylamine time-weighted average allowable concentration(PC-TWA)is 12mg/m3,short-term exposure tolerance(PC-STEL)is 24mg/m3.The existing standard detection methods for ethylamine and n-butylamine are polyethylene glycol:KOH:Chromosorb 103 and Chromosorb 103 packed column gas chromatography,the technology is relatively backward,and the minimum quantitative concentration of the method cannot meet the requirements of GBZ 2.1-2019 for the detection method;There is currently no standard test method for propylamine.Objective To establish an ion chromatography method for ethylamine,isopropylamine and n-butylamine in the air of workplaces.Methods According to the requirements of GBZ-2.1 "Occupational Exposure Limits for Hazardous Factors in the Workplace Part 1 Chemical Hazardous Factors"and GBZ/T210.4-2008 "Guidelines for the Establishment of Occupational Health Standards Part 4:Methods for Determination of Air Chemical Substances in Workplaces",Using dynamic gas distribution method to study sample collection methods,sampling efficiency and adsorption capacity;using ion chromatography to determine ethylamine,isopropylamine,and n-butylamine in the air in the workplace;measuring instrument conditions and eluent concentration,etc.Carry out optimization experiments to conduct standardized research and evaluation of method performance indicators such as linear range,detection limit,precision,accuracy,and desorption efficiency of the method.(1)Ethylamine:use a neutral silica gel tube to collect air samples at a flow rate of 500 mL/min for 15 minutes,and collect air samples at a flow rate of 50 mL/min for 240 minutes;the sample is desorbed with 10 mmol/L sulfuric acid solution;IonPac CS12A chromatographic column separation,column temperature The temperature is 25?,the flow rate is lml/min,and the concentration of methanesulfonic acid(MSA)eluent is 5mmol/L.It is qualitatively determined by the retention time of ethylamine cation and quantified by external standard curve method.(2)Isopropylamine:Use a neutral silica gel tube to collect air samples at a flow rate of 500 mL/min for 15 minutes,and collect air samples at a flow rate of 40 mL/min for 240 minutes;the sample is desorbed with 10 mmol/L sulfuric acid solution;IonPac CS12A chromatographic column separation,column temperature 25?,flow rate of 0.5ml/min,MSA eluent concentration of 10mmol/L,qualitatively determined by the retention time of isopropylamine cation,and quantified by external standard curve method.(3)n-Butylamine:Use a neutral silica gel tube to collect air samples at a sampling flow rate of 500mL/min for 15 minutes.The air samples are desorbed with 10mmol/L sulfuric acid solution;IonPac CS19 chromatographic column is separated,the column temperature is 30?,and the flow rate is lml/min.The concentration of the MSA eluent is 15mmol/L,which is qualitatively determined by the retention time of n-butylamine cation and quantified by the external standard curve method.Results(1)Ethylamine:the detection limit of the method was 4.29?g/L,the lower limit of quantification of the method was 14.29?g/L;the linearity was good in the range of 0-50?g/mL,the linear equation of the standard curve was y=0.1243x+0.0429,the correlation coefficient is r=0.9997;the lowest detected concentration is 0.004 mg/m3,and the lowest quantitative concentration is 0.012 mg/m3(calculated based on the 6.0L air sample);the desorption efficiency is 94.60%?99.23%;standard recovery The rate is 96.53%?99.99%;the intra-assay precision of the method is 1.00%-1.37%,and the inter-assay precision is 1.04%?1.68%;the suitable range of sampling flow is 50mL/min?100 mL/min;the sampling efficiency is 98.5%-99.6%;adsorption capacity is 730?g.(2)Isopropylamine:The detection limit of the method is 15.65?g/L,the lower limit of quantification is 52.17?g/L;the linearity is good in the range of 0?100?g/mL,the linear equation of the standard curve is y=0.0962x-0.0557,the correlation coefficient is r=0.9998;the lowest detected concentration is 0.013mg/m3,and the lowest quantitative concentration is 0.043 mg/m3(calculated based on the sample 6.0L);the desorption efficiency is 87.8%-99.2%;the standard recovery rate is 78.53%?93.27%;intra-assay precision is 1.14%?2.14%,inter-assay precision is 1.24%?2.30%;suitable range of sampling flow is 20mL/min?40 mL/min;sampling efficiency is 99.91%?100%;The adsorption capacity is 1642?g.(3)n-Butylamine:the detection limit of the method is 11.25?g/L,the lower limit of quantification of the method is 37.50?g/L;the linearity is good in the range of 0?100?g/mL,the linear equation of the standard curve is y=0.0713x-0.0327,the correlation coefficient is r=0.9992.The lowest detectable concentration is 0.008mg/m3,and the lowest quautitative concentration is 0.025 mg/m3(calculated based on 7.5L sample);the desorption efficiency is 91.50%?95.38%;the recovery rate of standard addition is 83.83%?100.02%;the precision within the batch It is 1.35%?2.30%,the precision between batches is 1.10%-2.20%;the sampling efficiency is 100%;the adsorption capacity is 2017?g.Conclusion The ion chromatography established in this study is a method for the determination of ethylamine,isopropylamine and n-butylamine in the air of workplaces.The performance indicators of the method meet the requirements of GBZ/T210.4-2008"Guidelines for the Establishment of Occupational Health Standards Part 4:Workplace Air" According to the requirements of "Methods for Determination of Chemical Substances",this method has high sensitivity and simple operation,and is suitable for the determination of the concentration of ethylamine,isopropylamine and n-butylamine in the air. |
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