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Abstract Introduction
PaperSpray is a rapid analysis technique which is particularly beneficial for the analysis of compounds in biological matrices, such as blood or urine. Because no sample preparation is required, and analysis times are as short as 1-2 minutes, this technique offers a strong competitive advantage over traditional methods which rely on chromatographic separation. Of particular interest in the clinical community are screening assays, which require short turnaround times and the ability to screen for multiple compounds in a single run. Here we present a method for rapid screening of 19 drugs of abuse compounds directly from dried urine spots, as well as quantification of 2 out of the 19 compounds.
Methods
For the screening method, a total of 19 compounds (Opiates, Amphetamines, Cocaine and PCP) were spiked into donor urine. Isotopically labelled internal standards were added. 4 concentration levels were prepared: at cutoff, 2 times higher than cutoff, 5 times lower than cutoff, and blank. Additionally, calibrator samples for cocaine and its metabolite benzoylecgonine were spiked into urine, covering the concentration range of 5-1000 ng/mL. For the quantification, QC samples were prepared at 3 additional concentrations. 8 uL of the respective urine sample was spotted onto paper for analysis. The spray solvent was 90% acetonitrile, 10% water, and 0.01 % acetic acid. Data was acquired for 1 min per sample, and each concentration level was measured 5 times for screening, and 3 times for quantitation. The Thermo Scientific™ TSQ QuantisTM MS was used for data acquisition, and TraceFinderTM was used for data analysis.
Results
All 19 compounds, met their respective screening cutoff levels (≤15% RSD of response ratio at the cutoff level, and the absolute AUC at least 4x higher than the AUC of the matrix blank). For Cocaine and Benzoylecgonine, calibration curves were constructed by integrating the resulting chronogram from 0.1 – 0.9 min. Both curves are linear over the tested concentration range and meet precision and accuracy requirements at the lowest calibrator level of 5 ng/mL (LOQ). All QC samples (low, middle, and high) are within 10% accuracy and 5% RSD for both, cocaine and benzoylecgonine.
Conclusion, References, Acknowledgements
PaperSpray technology can be used as a rapid screening method for drugs of abuse directly from dried urine spots. No sample preparation other than spiking an internal standard and spotting the urine samples on the paper is required. A total method length (analysis time + automated sample handling time) of 1.5 minutes makes it a highly efficient and competitive screening method.
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= Discovery stage.
= Translation stage.
= Clinically available.
