Determination of opiates, amphetamines and cocaine in whole blood, plasma and urine by UHPLC-MS/MS using a QuEChERS sample preparation

Importance of the topic

The accurate and rapid determination of opiates amphetamines and cocaine in whole blood plasma and urine is essential for forensic toxicology and the investigation of driving under the influence of drugs DUID cases

Study objectives and overview

This work set out to establish a fast sensitive and reliable UHPLC MS MS method combined with a QuEChERS sample preparation protocol to quantify 40 target analytes including opiate amphetamine and cocaine classes plus key metabolites in a single run and to benchmark its performance against classical extraction techniques

Methodology and instrumentation

Samples of 100 microliters of whole blood plasma or urine were fortified with isotopically labeled internal standards in acetonitrile followed by addition of QuEChERS salts and vortexing then chilling at minus 20 °C to induce protein precipitation and phase separation The upper organic layer was diluted with ammonium formate buffer and injected into a Shimadzu Nexera UHPLC system fitted with a 50 x 2.1 mm PFPP column Mobile phase A was 5 mM ammonium formate 0.1 percent formic acid in water and mobile phase B was a mixture of methanol acetonitrile 9 to 1 with 0.1 percent formic acid A rapid gradient from 15 to 100 percent B over five minutes was used The MS MS detection employed a Shimadzu LCMS 8040 with positive electrospray ionization and dynamically scheduled multiple reaction monitoring MRM transitions for each analyte

Main results and discussion

Chromatographic separation of critical isomeric pairs such as ephedrine pseudoephedrine and norephedrine norpseudoephedrine was achieved in under six minutes with baseline resolution The method delivered a lower limit of quantification of 5 micrograms per liter and an upper limit of 500 micrograms per liter Precision and accuracy were within 20 percent at the lowest level and below 15 percent at higher levels No significant matrix effects were detected and comparison with a reference GC MS method in authentic positive samples showed good agreement Notably no carry over was observed even after high concentration injections

Benefits and practical application

This protocol combines rapid QuEChERS based sample preparation with a short UHPLC run enabling high throughput screening and quantification of multiple drug classes from minimal sample volume Its simplicity robustness and low carry over make it well suited for routine DUID screening forensic casework and clinical toxicology laboratories

Future trends and potential applications

Further developments may include automation of the QuEChERS workflow integration with laboratory information management systems expansion of the analyte panel to emerging psychoactive substances and adaptation of the approach to alternative matrices such as oral fluid or hair Advances in UHPLC MS MS instrumentation could further reduce cycle times increase sensitivity and extend multiplexing capabilities

Conclusion

The combination of QuEChERS sample preparation and UHPLC MS MS detection provides a fast sensitive and reliable solution for simultaneous quantification of opiates amphetamines and cocaine in biological specimens fulfilling the demands of forensic and clinical toxicology

Reference

1 Dulaurent S Levi M Gaulier J M Marquet P Moreau S Determination of opiates amphetamines and cocaine in whole blood plasma and urine by UHPLC MS MS using QuEChERS sample preparation ASMS 2014 ThP599
2 Anastassiades J Lehotay S J Stajnbaher D Schenck F J Quick Easy Cheap Effective Rugged and Safe QuEChERS approach for analysis of pesticide residues J AOAC Int 86 2003 412 431