Interlaboratory comparison of thermospray and particle beam liquid chromatography/mass spectrometry interfaces: evaluation of a chlorinated phenoxy acid herbicide liquid chromatography/mass spectrometry analysis method

Abstract

Seven laboratories participated in an interlaboratory evaluation of a liquid chromatography / mass spectrometry (LC/MS) method for the analysis of 10 chlorinated phenoxy acid herbicides. The focus of this evaluation was to test the intercomparability of LC/MS data obtained from two types of LC/MS interfaces [i.e., thermospray (TS) and particle beam (PB)]. Eight simulated sample extracts were sent to each laboratory for LC/MS analysis. There were statistically significant differences between interfaces in the quantitative data for all analytes except 2-(2,4,5-trichlorophenoxy)propanoic acid (silvex). Particle beam exhibited a high positive bias and a low relative standard deviation at the highest sample extract concentration range, 500 pg/mL, while TS showed a low bias and a low relative standard deviation at the lowest sample extract concentration range, 5 pg/mL. Another factor of this study was to look for any performance differences between interfaces of the same type, but differing manufacturers. A statistical difference was observed, between PB interfaces, for 2-(l-methylpropyl)-4,6-dinitrophenol (dinoseb).

Evidence for thermal decomposition contributions to the mass spectra of chlorinated phenoxyacid herbicides obtained by particle beam liquid chromatography mass spectrometry

“…Ii i J Am Soc Mass Spectrom 1992, 3, 823-830 noxyacid herbicides, namely, 2,4,5-T and Silvex. Data received from other laboratories during an interlaboratory study on the application of LC/MS to the analysis of phenoxyacid herbicides also exhibit considerable mass spectral variation using particle beam type LC/MS instruments [19]. Variation in the particle beam mass spectra of phenoxyacid herbicides appears to be characteristic for this class of compounds.…”

High‐Performance Liquid Chromatography/Mass Spectrometry Methods in Pesticide Analysis

“…A comparison between PB and TSP in the analysis of phenoxy acid herbicides was reported in another paper. 48 TSP with NI detection showed better sensitivity, whereas the PB was more precise, particularly at the high concentration levels.…”

Intercalibration of Chromatographic Methods in Multiresidue Pesticide Determination

“…In particular, GC methods for the analysis of ureic-, 2-4 triazinic-, [5][6][7][8][9][10][11][12][13][14] and phenoxyacidic-(after derivatisation) 15,16 pesticides are reported. [18][19][20][21][22][23][24][25][26] Multiresidual methods using HPLC were developed in the last years thanks also to the introduction of the hyphenation with massspectrometry. 17 On the other hand, HPLC application is suitable for the analysis of non-volatile, thermolabile or highly polar compounds, such as phenoxyacids.…”