| Amines in fine particles constitute a significant fraction of secondary organic aerosols and have adverse effects on air quality and human health.However,due to the relatively high volatility,strong polarity and low environmental concentration of low molecular weight amines,it is subjected from great difficulty to accurately measure their abundances.The constituents,concentrations and potential sources of low molecular weight amines in fine particles are still unclear.In this study,a determination method based on LC-MS was developed to qualitatively and quantificationally detect particulate amines.The pollution characteristics and potential sources of fine particulate amines in fine particles at the coastal Qingdao in winter were investigated in this study.The separation of different amine compounds was performed with a Hydrophilic Interaction Liquid Chromatography(HILIC)column,and the mobile phase consisted of methanol and ammonium formate in deionized water.Fifteen amines were identified in fine particles in coastal Qingdao based on standards and characterisitic MS fragments,including eleven aliphatic amines,alcohol amine,two alicyclic amines,and aromatic amine,which were MA,DMA,TMA,EA,DEA,TEA,PA,DPA,TPA,BA,DBA,MOR,PYR,AN and MEA.The contents of amines were quantified by using internal standard and multipoint calibration curves.The limits of detection were 0.59-75.5 ng mL-1.The recovery rates of the 15 amines ranged from 59%to 92%.The PM2.5 filter samples were collected during winter of 2018 and 2019,which were extracted with methanol and then analyzed by using the developed LC-MS method.The average concentration of total amines in PM2.5 samples was approximately 130 ng m-3,and the mean concentrations of individual amines ranged from 0.1 to 86.3 ng m-3.Dimethylamine was the most abundant species,which in total contributed approximately 50%.There are no significant discrepancies in the concentrations and compositions of decteted amines in fine particulate matters between daytime and nighttime.The amines in PM2.5 usually exhibited elevated concentrations in the presence of high levels of SO2 and NOx or in the condition of high relative humidity.A receptor model of positive matrix factorization(PMF)was employed to undersdand the sources of amines in fine particles.Six major sources were identified,including coal combustion,industrial production,vehicle exhaust,biomass burning,agricultural and marine emissions,and secondary formation.Surprisingly,most of 15 amines in fine particles primarily originated from the anthropogenic emissions particularly related to coal combustion and industrial productions.Strict control measures should be adopted to address the amine pollution.In summary,a determination method was developed for measurement of amines in particle samples,which provides technical support for the deep studies on amines.The composition,concentrations,and main sources of amines in fine particles in coastal Qingdaoao in winter,enriching the scientific knowledge on atmospheric amines and providing suggestions for the control of atmospheric particulate matter pollution. |
