MALDI Orbitrap mass spectrometry for fast and simplified analysis of novel street and designer drugs.

BACKGROUND: New strategies of rapid high-throughput analysis of street drugs without time-consuming sample preparations are necessary due to the massive variety of illicit substances available on the market. METHODS: We used matrix-assisted laser desorption/ionization (MALDI) high-resolution mass spectrometry (HRMS) to identify substances in 74 drug samples obtained from anonymous drug users who participate in the drug prevention initiative "checkit!". We compared our methodology with results derived from "checkit!" where samples are analyzed by high performance liquid chromatography (HPLC) coupled to ultraviolet diode array detection (UV-DAD) as well as single Quad-MS. Reference substances were serially diluted for calibration curves to assess the possibility of obtaining quantitative information with MALDI using an ionic liquid matrix. RESULTS: All drug substances found by "checkit!" analysis were also identified by MALDI HRMS full scan without previous chromatographic separations, including the detection of additionally 16 substances not detected by "checkit!". Reference substances such as cocaine, lysergic acid diethylamide, levamisole and papaverine were detectable using the ionic liquid matrix N,N-diisopropylethylammonium α-cyanohydroxycinnamate. Serial dilutions revealed correlation coefficients ranging from 0.95 to 0.99. CONCLUSION: Considering the growing complexity in the analysis of designer drugs the presented method can be used either in parallel or instead of already established drug identification techniques as a fast and comprehensive primary screening tool.

Matrix-assisted laser desorption/ionization for simultaneous quantitation of (acyl-)carnitines and organic acids in dried blood spots.

RATIONALE: Screening for inborn errors of metabolism using mass spectrometry is part of nationwide newborn screening programs and involves the detection of disease relevant (acyl-)carnitines and organic acids from dried blood spots. Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS) is a well-established tool for proteomics approaches. In recent years, this technique has become more and more integrated in analysis and identification of small metabolites and disease biomarkers in daily clinical laboratories. METHODS: We used a combination of both MALDI and high-resolution accurate mass (HR/AM) mass spectrometry using a linear ion trap-Orbitrap for the identification of small molecules from dried blood spots that serve as biomarkers for inborn errors of metabolism. The levels of detected metabolite species were compared between healthy newborns and affected patients with various inborn errors of metabolism using isotopically labeled internal standards and new bioinformatics software, respectively. RESULTS: (Acyl-)carnitine levels from normal and affected patients could be quantified and differentiated. Additionally, using the high resolving power of full scan Orbitrap mass spectrometry and novel software tools we demonstrated the identification and quantification of disease-specific organic acids. CONCLUSIONS: MALDI-HR/AM and full scan spectra to obtain information for the metabolic status of patients is a promising complementary approach to electrospray ionization mass spectrometry by simplified sample preparation, facilitating the screening of hundreds of metabolites from small sample volumes.