Negative APCI-LC/MS/MS Method for Determination of Natural Persistent Halogenated Products in Marine Biota

Abstract

A sensitive and selective method utilizing high performance liquid chromatography coupled to negative atmospheric pressure chemical ionization tandem mass spectrometry (APCI-LC/MS/MS) was developed to enable analysis of selected natural persistent organohalogens accumulated in marine biota. The analytes were three methoxylated tetrabromodiphenyl ethers (6-MeO-BDE47, 2'-MeO-BDE68, and 2',6-diMeO-BDE68), a dimethoxylated tetrabromobiphenyl (2,2'-diMeO-BB80), and two halogenated methyl bipyrroles (Cl(7)-MBP and Br(4)Cl(2)-DBP). These products were well resolved on a 150 mm reversed-phase column with methanol as the mobile phase. The fragmentation pathways of the Cl(7)-MBP and Br(4)Cl(2)-DBP produced characteristic multiple reaction monitoring (MRM) transitions. Determination was performed in the MRM mode using phenoxide ion [M-Br+O](-) and product Br(-) ions for MeO-BDE analogues, or the precursor [M-Cl+O](-) to Br(-) ion for Br(4)Cl(2)-DBP, and to C(4)NCl(4)(-) ion for Cl(7)-MBP. The APCI-LC/MS/MS method is acceptable for calibration of the linearity and repeatability of all products studied in the low ng/g (lipid weight) level and with similar sensitivity to the electron ionization (EI)-GC/MS method. The proposed method was applied for quantification of natural organohalogens accumulated in melon-headed whale (Peponocephala electra) blubber (N = 15) in the Asia-Pacific Ocean. The concentration was positively correlated between different groups of compounds except for 2'-MeO-BDE68. The use of the analytical method based on negative ion APCI-LC/MS/MS would provide a new way for rapid monitoring of halogenated natural products from marine biota, such as sponges or algae.

Analysis of hydroxylated polybrominated diphenyl ether metabolites by liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry

“…Other methods of analysis have been used in recent studies to analyze PBDEs and phenolic compounds 16–21. Two studies by Riu et al 21.…”

“…Although dansyl chloride derivatization is faster than diazomethane derivatization, there is still need for additional cleanup after the reaction is complete. The application of atmospheric pressure chemical ionization tandem mass spectrometry (APCI‐MS/MS) in the analysis of methoxylated PBDEs and two OH‐PBDEs has also been reported 18, 19. Low parts per billion detection limits were achieved with this technique.…”

Sample preparation method for the speciation of polybrominated diphenyl ethers and their methoxylated and hydroxylated analogues in diverse environmental matrices

“…Although some works used LC-MS/MS methods for the analysis of PBDEs and MeO-PBDEs [29][30][31], the high quantification limits made it unsuitable for the detection of trace PBDEs and MeO-PBDEs in environmental samples. OH-PBDEs can be determined by GC/MS as their MeOanalogues via a methylated derivatization using diazomethane [10,25,26,32], but the toxicity and easy explosive of diazomethane make the analysis difficult to handle.…”

Recent Methodologies for Brominated Flame Retardant Determinations by Means of Liquid Chromatography–Mass Spectrometry

“…A selective and sensitive method using negative LC-APCI-MS-MS [69] was also developed to enable analysis of selected natural persistent organohalogens accumulated in marine biota. Selected analytes were three MeO-tetraBDEs, a diMeO-tetraBDE and two halogenated methyl bipyrroles (Cl 7 Finally, a LC-ESI-MS-MS method with greater sensitivity and better separation efficiency [70] was established for the simultaneous analysis of four estrogens, BPA, 10 OH-PBDEs, and 15 brominated phenols (BRPs) in blood plasma sample, using dansyl chloride as derivatization agent that reacts, which provides a new method to derivatize phenolic compounds prior to LC-MS analysis.…”