Comparison of electrospray ionization, atmospheric pressure photoionization, and anion attachment atmospheric pressure photoionization for the analysis of hexabromocyclododecane enantiomers in environmental samples.
Anion attachment atmospheric pressure photoionization (AA-APPI) has been suggested as a means of expanding the range of compounds that may be analyzed by LC-MS, and has been found to enhance the ionization of some macromolecules (e.g., peptides, polymers) that were unable to be ionized by other techniques. In this study, AA-APPI was compared to APPI, using hexabromocyclododecane (HBCD) enantiomers as a model compound, to provide proof of principle of the use of AA-APPI for small molecule analysis. The use of AA-APPI, with 1,4-dibromobutane in toluene as a bromide source, offered increased sensitivity and lower limits of detection than APPI. Minimal matrix effects were found with AA-APPI in sediment extracts spiked with HBCD post-extraction, with less than a 6% enhancement in the ion signal. Furthermore, enantiomer fractions of HBCD enantiomers were racemic in spiked sediment extracts, in contrast to the more commonly used technique of electrospray ionization, for which matrix effects caused ion signal modification to cause non-racemic measurement artifacts. The use of AA-APPI offers a simple means of further extending the range of compounds ionizable by AA-APPI while maintaining minimal matrix effects.
University of Alberta, Department of Chemistry, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada.
Matthew S
MS
Ross
Charles S
CS
Wong
D001274:Atmospheric Pressure; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D019015:Geologic Sediments / Q000737:chemistry*; D006842:Hydrocarbons, Brominated / Q000032:analysis* / Q000737:chemistry; D016014:Linear Models; D000432:Methanol / Q000737:chemistry; D055668:Photochemical Processes; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry / Q000379:methods
D006842:Hydrocarbons, Brominated; C089796:hexabromocyclododecane; D000432:Methanol