Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden.
Anal Chem. 2012 May 1;84(9):3965-72. doi: 10.1021/ac203005r. Epub 2012 Apr 17.
The detection capabilities of single particle inductively coupled plasma-mass spectrometry (spICPMS) with respect to particle size and number concentrations are investigated for the case of silver nanoparticles (ca. 20-80 nm). An iterative algorithm was developed where particle measurement events were distinguished as outliers from the more continuous dissolved ion signal if the measured intensity was more than five times the standard deviation of the whole data set. The optimal dwell time for 40-80 nm particles, limiting both incomplete and multiple particle events, was 5 ms. The smallest detectable particle size (ca. 20 nm) is mainly limited by the overlap of particle events and dissolved signal that increases with noise on both signals. The lowest measurable number concentration is limited by the relative frequency of erroneously identified particle events, a limit that can be reduced by acquiring more data points. Finally, the potential of spICPMS for environmental detection of nanoparticles is demonstrated for a wastewater treatment plant effluent sample.
研究了单颗粒电感耦合等离子体质谱（spICPMS）在银纳米粒子（约 20-80nm）情况下对粒径和数浓度的检测能力。开发了一种迭代算法，如果测量强度超过整个数据集标准偏差的五倍，则将颗粒测量事件与更连续的溶解离子信号区分开来作为异常值。对于 40-80nm 颗粒，限制不完全和多个颗粒事件的最佳停留时间为 5ms。最小可检测粒径（约 20nm）主要受颗粒事件和溶解信号的重叠限制，而重叠信号随噪声的增加而增加。最低可测量的浓度受错误识别颗粒事件的相对频率限制，可以通过采集更多的数据点来降低该限制。最后，通过处理废水处理厂废水样本，展示了 spICPMS 用于环境检测纳米颗粒的潜力。
