Evaluation of a particle trap laser desorption mass spectrometer (PT-LDMS) for the quantification of sulfate aerosols
Evaluation of a particle trap laser desorption mass spectrometer (PT-LDMS) for the quantification of sulfate aerosols
复制标题
评估粒子阱激光解吸质谱仪 (PT-LDMS) 对硫酸盐气溶胶的定量
DOI：
10.1080/02786826.2016.1139685
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发表时间：
2016
影响因子：
5.2
通讯作者：
N. Hirayama and N. Takegawa
中科院分区：
文献类型：
--
作者：
Ozawa;Y.;N. Takeda;T. Miyakawa;M. Takei;N. Hirayama and N. Takegawa
研制了一种用于在线测量亚微米气溶胶粒子化学组成的粒子阱激光解吸质谱仪（PT-LDMS）。通过实验室和环境测量对PT-LDMS进行了评估，重点是硫酸盐气溶胶的定量。硫酸铵（（NH 4）2SO 4）通常是城市空气中硫酸盐气溶胶的主要形式;因此，它被用作实验室实验和校准的材料。在48（SO+）和64（SO2+）的质荷比（m/z）下观察到（NH 4）2SO 4的主要碎片。研究了灵敏度（以m/z48信号与硫酸根质量的比值表示）与激光功率和池温度的关系。在东京进行了PT-LDMS与商业硫酸盐颗粒分析仪（SPA）和过滤器采样的相互比较。SPA法与滤波法具有良好的一致性（斜率= 0.98，r2 = 0.99）。虽然PT-LDMS测定的硫酸盐质量浓度与SPA测定的硫酸盐质量浓度具有密切的相关性，但PT-LDMS测定的硫酸盐质量浓度往往低估SPA测定的硫酸盐质量浓度（斜率= 0.70，r2 = 0.96）。虽然这种差异可以主要归因于PT-LDMS（大约PM 1）和SPA（PM2.5）之间的尺寸切割差异，但蒸发效率的差异也很重要。版权所有© 2016美国气溶胶研究协会
A particle trap laser desorption mass spectrometer (PT-LDMS) has been developed for the online measurements of the chemical composition of submicron aerosol particles. The PT-LDMS was evaluated by both laboratory and ambient measurements, with the focus being the quantification of sulfate aerosols. Ammonium sulfate ((NH4)2SO4) is generally the predominant form of sulfate aerosols in urban air; hence, it is used as a material for laboratory experiments and calibration. Major fragments of (NH4)2SO4were observed at mass-to-charge ratios (m/z) of 48 (SO+) and 64 (SO2+). The dependence of sensitivity (expressed as the ratio ofm/z48 signal to sulfate mass) on laser power and cell temperature was investigated. An intercomparison of PT-LDMS with a commercial sulfate particle analyzer (SPA) and filter sampling was performed in Tokyo. Good agreement was observed between SPA and filter analysis (slope = 0.98,r2= 0.99). Although the mass concentration of sulfate measured by PT-LDMS exhibited a tight correlation with that measured by SPA, the mass concentration measured by PT-LDMS tended to underestimate that measured by SPA (slope = 0.70,r2= 0.96). While the discrepancy can be mainly attributed to the difference in size cut between PT-LDMS (approximately PM1) and SPA (PM2.5), differences in vaporization efficiency were also found to be important.Copyright © 2016 American Association for Aerosol Research