Comparison of two extraction procedures for determination of drugs of abuse in human saliva by high-performance liquid chromatography.
High performance liquid chromatography in combination with diode array detection (HPLC-DAD) was used to determine morphine, 6-acetylmorphine, cocaine, benzoylecgonine, cocaethylene, methadone and 2-ethylene-1,5-dimethyl-3,3,-diphenylpyrrolidine in human saliva. For comparison, samples were prepared by either liquid-liquid extraction in Toxitubes A or microwave-assisted extraction (MAE), by mixing 1 ml of saliva with 10 ml of chloroform and operating at 100 degrees C for 10 min. Acetonitrile and 0.02 m phosphate buffer at pH 6.5 were used as mobile phase in HPLC in gradient mode. The detector response was linear over the drug concentration range of 0.05-2.0 microg ml(-1) in human saliva. The analytical method was validated by determining its precision and accuracy (n = 5), which were lower than 5% as relative standard deviation and 6% as relative error. Limits of detection ranged from 10 to 35 ng ml(-1); mean recoveries of drugs were from 53 to 95% with Toxitubes A and from 83 to 100% with MAE at two different concentrations (0.1 and 1.0 microg ml(-1)). The proposed method was applied to 24 saliva samples from individuals poisoned with opiates and/or cocaine.
Fernández
P
P
Institute of Legal Medicine, Forensic Toxicology Service, Faculty of Medicine, Santiago de Compostela, Spain. imlpuri@usc.es
Morales
L
L
Vázquez
C
C
Lago
M
M
Bermejo
A M
AM
D002021:Buffers; D002138:Calibration; D002725:Chloroform; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D013287:Illicit Drugs / Q000737:chemistry / Q000302:isolation & purification*; D008872:Microwaves; D012015:Reference Standards; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry*; D012996:Solutions; D012997:Solvents; D015813:Substance Abuse Detection / Q000379:methods*; D019966:Substance-Related Disorders / Q000175:diagnosis*
D002021:Buffers; D013287:Illicit Drugs; D012996:Solutions; D012997:Solvents; D002725:Chloroform