Determination of N-nitrosamines in Water by Gas Chromatography Coupled with Electron Impact Ionization Tandem Mass Spectrometry

Abstract

This study assessed analysis of N-nitrosamines by separation, identification, and quantification using a gas chromatography (GC) mass spectrometer (MS) with electron impact (EI) mode. Samples were pretreated by a automated solid phase extraction (SPE) and a nitrogen concentration technique to detect low concentration ranges. The analysis results by EI-GC/MS (SIM) and EI-GC/ MS/MS (MRM) on standard samples with no pretreatment exhibited similar results. On the other hand, the analysis of pretreated samples at low concentrations (i.e. ng/L levels) were not reliable with a EI-GC/MS due to the interferences from impurity peaks. The method detection limits of eight (8) N-nitrosamines by EI-GC/MS/MS analysis ranged from 0.76 to 2.09 ng/L, and the limits of quantification ranged from 2.41 to 6.65 ng/L. The precision and accuracy of the method were evaluated using spiked samples at concentrations of 10, 20 and 100 ng/L. The precision were 1.2~13.6%, and the accuracy were 80.4~121.8%. The R 2 of the calibration curves were greater than 0.999. The recovery rates for various environmental samples were evaluated with a surrogate material (NDPA-d14) and ranged 86.2~122.3%. Thus, this method can be used to determine low (ng/L) levels of N-nitrosamines in water samples.

Comparison of EI-GC-MS/MS, APCI-LC-MS/MS, and ESI-LC-MS/MS for the Simultaneous Analysis of Nine Nitrosamines Eluted from Synthetic Resins into Artificial Saliva and Health Risk Assessment

“…The analytical conditions for GC and LC were optimized by referring to previous studies on the simultaneous analysis of nitrosamines using GC-MS/MS and LC-MS/MS, and the nitrosamine analysis guidelines of domestic and overseas countries. In previous studies using GC [13][14][15][16][17], the WAX column in which the stationary phase is ethylene glycol is used most frequently in the analysis of nitrosamines. We selected the DB-WAX UI (30 m × 0.25 mm, 0.25 µm) column accordingly.…”

“…In the past, the GC method mainly referred to the gas chromatography-thermal energy analysis (GC-TEA), which is a traditional method with a high selectivity for Nnitroso compounds using thermal decomposition [12]. However, since MS with a higher sensitivity than GC-TEA has been developed, GC-MS(MS) (single or tandem MS) has been applied to analyze nitrosamines in several studies, as well as in Method 521 of the U.S. EPA [13][14][15][16][17]. The LC method has been reported to enable the simultaneous measurement of nitrosamines eluted into artificial saliva and has been verified as an alternative to the traditional GC-TEA method of the EU [2].…”