Analysis of Phencyclidine in Urine to U.S. SAMHSA Guidelines with LC/MS/MS and GC/MS

Importance of the Topic

Phencyclidine analysis in urine plays a crucial role in forensic toxicology and compliance with regulatory guidelines set by U.S. SAMHSA. Accurate detection at low concentration is essential for drug abuse monitoring, workplace testing, and clinical investigations.

Objectives and Overview

This study evaluates a streamlined sample preparation method using Agilent Bond Elut Certify mixed mode solid phase extraction combined with LC MS MS and GC MS techniques to meet the 25 ng mL cutoff for PCP in urine defined by SAMHSA. The goal is to demonstrate robust performance across multiple instrument platforms with a common extraction protocol.

Methodology and Instrumentation

This approach uses 1 mL human urine spiked with PCP and PCP d5 internal standard adjusted to pH 6 0 by KH2PO4 buffer. Agilent Bond Elut Certify mixed mode SPE cartridges exploit reversed phase and cation exchange to retain PCP while removing interferences. The workflow involves equilibration with methanol and buffer, sample loading, washing with acetic acid and methanol, followed by elution with acetonitrile plus ammonia. Extracts for LC MS MS are reconstituted in 30 70 acetonitrile water with formic acid and for GC MS in hexane.

Instrumentation

LC MS MS was performed on an Agilent Infinity 1260 LC coupled to a 6460 triple quadrupole with JetStream electrospray ionization. Chromatography used a Pursuit XRs Ultra Diphenyl column and a gradient of formic acid aqueous and acetonitrile mobile phases. MRM transitions monitored PCP and PCP d5. GC MS analyses utilized an Agilent 7890A gas chromatograph with 5975C mass selective detector and a DB 5ms column. Both pulsed splitless and pulsed split injection modes were evaluated in SIM mode targeting characteristic ions of PCP and PCP d5.

Key Results and Discussion

Calibration curves were linear from 1 to 500 ng mL with R2 values exceeding 0 9996 for all methods. The limit of quantitation was 1 ng mL for LC MS MS and 5 ng mL for GC MS. Accuracy recoveries ranged from 92 9 to 101 and precision RSDs were below 4 4 across tested concentrations. Third party QC samples at 19 ng mL remained within 20 percent accuracy throughout the batch. Chromatograms at the 25 ng mL cutoff demonstrated clear separation of PCP and internal standard, confirming method selectivity and sensitivity.

Benefits and Practical Applications

The single SPE procedure reduces solvent use and simplifies workflows by providing instrument independent sample prep. Laboratories can choose LC MS MS or GC MS based on availability and throughput needs without altering extraction. High sensitivity at or below the mandatory cutoff supports workplace drug testing, forensic investigations and clinical toxicology.

Future Trends and Potential Applications

Emerging MS technologies may further lower detection limits and increase throughput. Automation of SPE and integration with online sample preparation could streamline routine screening. Cross platform validated methods like this can be extended to other basic drugs and matrices to support comprehensive toxicology panels.

Conclusion

Agilent Bond Elut Certify mixed mode SPE coupled with LC MS MS or GC MS provides a robust and versatile method for PCP analysis in urine. The approach achieves regulatory compliance with excellent linearity, accuracy and precision using a unified sample preparation protocol. Such flexibility benefits forensic and clinical laboratories by enabling consistent results across diverse instrumentation.

References

• A Ishii et al International Journal of Legal Medicine 108 244 1996
• C Moore C Coulter K Crompton Detection of Phencyclidine in Human Oral Fluid Using Solid Phase Extraction and Liquid Chromatography with Tandem Mass Spectrometric Detection Agilent Technologies Application Note 5989 8084EN 2008