Improved tandem mass spectrometry (MS/MS) derivatized method for the detection of tyrosinemia type I, amino acids and acylcarnitine disorders using a single extraction process

Simultaneous quantitation of hexacosanoyl lysophosphatidylcholine, amino acids, acylcarnitines, and succinylacetone during FIA–ESI–MS/MS analysis of dried blood spot extracts for newborn screening

“…The analyte enrichment of human blood utilized commercially available standards prepared as stock solutions (in water or methanol) and their concentrations were verified by comparison of diluted analyte peak areas to commercially available stable-isotope labeled AA, AC, and SUAC. Our results indicated that the recoveries of AA, AC, and C26:0-LPC were similar to the results obtained from two separate methods (AA–AC–SUAC [5] and C26:0-LPC [14]), and that the quantitation of SUAC was slightly less sensitive than NSQAP's in-house AA–AC–SUAC method. Anonymous residual DBS specimens from presumed normal newborns (N = 151) were assayed to determine the mean and 95% confidence interval of C26:0-LPC, and to confirm that AA, AC, and SUAC quantitation was similar to aggregate NBS data from the Region 4 Stork MS/MS Collaborative (R4S) [4,16].…”

“…Early detection, diagnosis, and treatment of inborn errors of metabolism prevent disability and death [2]. Flow injection analysis–electrospray ionization–tandem mass spectrometry (FIA–ESI–MS/MS) is the most widely used method to quantitate AA and AC in DBS extracts because it is rapid, sensitive, specific, and easily multiplexed for 20 to 30 analytes of interest and their corresponding stable-isotope labeled internal standards used for quantitation [3–5]. …”

“…A variety of DBS extraction procedures have been published and/or incorporated into commercial products [5–7]. Criteria for a widely applicable procedure include simplicity, rapidity, avoiding expensive or hazardous reagents, and the ability to extract biomarkers with a variety of chemical properties [e.g.…”

“…Some methods derivatize AA, AC, and SUAC to form butyl esters [8] while other methods do not [9]. A hydrazine derivatization of SUAC is commonly used to improve its positive-mode ionization efficiency [5]. …”

Derivatization in liquid chromatography for mass spectrometric detection

“…The formed derivatives, such as esters or amides, were efficiently fragmented upon CID and were suitable for SRM. Butanol-HCl was sometimes used for the derivatization of carboxylic acids (62)(63)(64)(65). The generated butyl esters were rather hydrophobic and often gave the characteristic product ions.…”