利用紫外光离子源高场不对称波形离子迁移谱快速、现场检测水中氨的含量

氨是水体主要的污染物之一,其含量是水质评估的重要参数。本研究采用真空紫外光离子源-高场不对称波形离子迁移谱(Ultraviolet photoionization high field asymmetric waveform ion mobility spectrometry, UVFAIMS)技术,发展一种的水中氨含量的现场快速检测方法。通过对比标准氨样品和水中微量氨UV-FAIMS 谱图峰的特征补偿电压(Compensation voltage, CV)值,确定了水中HN+4的特征离子峰位置；研究了不同分离电压(Dispersion voltages, DV)下HN+4谱图峰位置的关系,获得了HN+4的特征识别系数α2和α4分别为2.21×10-5 Td-2和-1.45323×10-9 Td-4；通过不同浓度样品的信号响应,研究了UV-FAIMS 对水中氨的检出限,在信噪比为3的情况下达到了9.2 μg/ L。本研究为水中氨现场检测提供了一种快速、无需前处理的技术手段。

Direct and Rapid Determination of Ammonia in Water Samples Using Ultraviolet Photoionization High Field-Asymmetric Waveform Ion Mobility Spectrometry

A novel on-site rapid detection method for ammonia detection in water was developed by using ultraviolet photoionization high field-asymmetric waveform ion mobility spectrometry ( UV-FAIMS ) . The position of ammonia characteristic ion peak was acquired by the comparison between the characteristic compensation voltage ( CV) in standard ammonia sample and trace amount ammonia in water. The relation between the positions of ammonia characteristic ion peaks under different dispersion voltages ( DV ) was studied. The values of α2,α4 were 2. 21 ×10-5 Td-2 and -1. 45323 ×10-9 Td-4, respectively. The different concentrations of ammonia in water was measured with a limit of detection (LOD) of 9. 2 μg/L (S/N=3). This study provided a rapid, non-pretreatment means for the detection of ammonia in water matrices.