Zhang Weiguo, Wu Ping, Li Chongjiu
College of Science, China Agricultural University, Beijing 100094, China.
Rapid Commun Mass Spectrom. 2006;20(10):1563-8. doi: 10.1002/rcm.2473.
The effects of overlapping levels and concentration ratios of overlapping components, and of scan rates of the mass spectrometer, on the capability of the automated mass spectral deconvolution and identification system (AMDIS) in pesticide residue analysis were studied. To investigate the capability of AMDIS in removing interferences from the overlapping peaks, this system was applied to data files obtained from the gas chromatography/mass spectrometry (GC/MS) analysis of two overlapping (co-eluting) pesticides (beta-HCH and PCNB) in full scan mode. Differences in overlap levels, the concentration ratios of the two overlapping components and the scan rates of the instrument were studied. When the difference in scan number of overlapping compounds was equal to 1 scan, AMDIS incompletely extracted 'purified' mass spectra but as the difference increased to 3 or more scans, complete correct spectra could be extracted. The results also show that when the scan rate was in the range of 0.4-0.90 s/scan and the concentration ratios of the target compound/interference were above 1/5, there were ideal deconvolution results for this approach. To further study the application of AMDIS to pesticide residue analysis, AMDIS was applied to the identification of pesticides spiked in real samples (cabbage and rice). Typical pesticides being evaluated were identified using AMDIS at concentrations >50 ng/g in the extracts.
研究了重叠组分的重叠水平和浓度比以及质谱仪扫描速率对农药残留分析中自动质谱解卷积与鉴定系统（AMDIS）性能的影响。为了研究AMDIS去除重叠峰干扰的能力，该系统应用于在全扫描模式下对两种重叠（共洗脱）农药（β-六六六和五氯硝基苯）进行气相色谱/质谱（GC/MS）分析所获得的数据文件。研究了重叠水平、两种重叠组分的浓度比以及仪器扫描速率的差异。当重叠化合物的扫描次数差异等于1次扫描时，AMDIS不能完全提取“纯化”的质谱，但随着差异增加到3次或更多次扫描时，可以提取完整正确的光谱。结果还表明，当扫描速率在0.4 - 0.90 s/扫描范围内且目标化合物/干扰物的浓度比高于1/5时，该方法有理想的解卷积结果。为了进一步研究AMDIS在农药残留分析中的应用，将AMDIS应用于实际样品（卷心菜和大米）中添加农药的鉴定。在提取物中浓度>50 ng/g时，使用AMDIS对正在评估的典型农药进行了鉴定。
