Gas chromatography/mass spectrometry of polychlorinated biphenyls using atmospheric pressure chemical ionization and atmospheric pressure photoionization microchips

Abstract

Gas chromatography (GC) and ion trap mass spectrometry (MS) were combined with microchip atmospheric pressure chemical ionization (microAPCI) and microchip atmospheric pressure photoionization (microAPPI) sources. Selected polychlorinated biphenyls (PCBs, IUPAC Nos. 28, 52, 101, 118, 138, 153 and 180) were analyzed by GC/microAPCI-MS and GC/microAPPI-MS to demonstrate the applicability of the miniaturized ion sources in negative ion mode analysis. The microAPCI and microAPPI methods were evaluated in respect of detection limit, linearity and repeatability. The detection limits for the PCB congeners were somewhat lower with microAPCI than with microAPPI, whereas microAPPI showed slightly wider linear range and better repeatability. With both methods, the best results were obtained for highly chlorinated or non-ortho-chlorinated PCBs, which possess the highest electron affinities. Finally, the suitability of the GC/microAPPI-MS method for the analysis of PCBs in environmental samples was demonstrated by analyzing soil extracts, and by comparing the results with those obtained by gas chromatography with electron capture detection (GC/ECD).

Analysis of selective androgen receptor modulators by gas chromatography-microchip atmospheric pressure photoionization-mass spectrometry

“…In addition, the possibility to couple the API microchip with a high-resolving power Orbitrap MS, enabling highresolution MS analysis together with GC, is demonstrated (GC-APCI-Orbitrap MS). While the advantages of the heated nebulizer microchip for analytical work, i.e., high sensitivity and an insignificant dead volume, have been demonstrated in previous studies [9,11], this study further shows the feasibility of the heated nebulizer microchip in bioanalytical applications. In comparison with the matrices in the previous GC-APPI-MS and GC-APCI-MS applications, the biological sample matrix of the present study is more challenging.…”

“…The heated nebulizer microchips can be used to connect a capillary liquid chromatograph (cap LC) [8,9] or a gas chromatograph (GC) [9 -11], with any mass spectrometer with an atmospheric pressure ionization (API) source, or as a heated sprayer in desorption atmospheric pressure photoionization [12]. In addition, the heated nebulizer microchips have been shown to be suitable for the analysis of steroids [8,9], polyaromatic hydrocarbons [9], and drugs of abuses [13,14], as well as for quantitation of polychlorinated biphenyls from soil samples [11].…”

Ionization of EPA Contaminants in Direct and Dopant-Assisted Atmospheric Pressure Photoionization and Atmospheric Pressure Laser Ionization

“…There are, therefore, plenty of possible proton donors present, and the conditions are no longer well-defined, as they were in [15]. Similarly to [15], the experiment was repeated using toluened 8 ions. The source of the proton is, therefore, likely to depend on the conditions (i.e., the presence of possible proton-donors) that exist in the ion source at the time of elution.…”

“…As an LC-MS interface, APPI has been applied widely in e.g., pharmaceutical, biological, and environmental analysis [3,4]. Although APPI was originally developed for LC-MS, there is also an increasing number of reports using it as an interface for GC-MS [5][6][7][8][9][10][11][12]. A major advantage of GC compared with LC is its much higher peak capacity, which allows the separation of a much higher number of compounds in one chromatographic run.…”

Analysis of Chlorothalonil by Liquid Chromatography/Mass Spectrometry Using Negative-ion Atmospheric Pressure Photoionization

“…14 As does the rearrangement of polychlorinated aromatic hydrocarbons with O2 generate characteristic phenoxides in a process of negative chemical ionization, 16,17 it is inferred that chlorothalonil was also transformed to [M-Cl+O] -by negative-ion APPI. A similar phenoxide was generated for dacthal-d6.…”