Assay of Delta9-tetrahydrocannabinol (THC) in oral fluid-evaluation of the OraSure oral specimen collection device.

TY - JOUR

T1 - Assay of Delta9-tetrahydrocannabinol (THC) in oral fluid-evaluation of the OraSure oral specimen collection device.

AU - Kauert, Gerold F

AU - Iwersen-Bergmann, Stefanie

AU - Toennes, Stefan W

PY - 2006

Y1 - 2006

N2 - Oral fluid is considered to be an alternative to urine testing for the detection of acute ingestion of drugs. The OraSure Intercept DOA Oral Specimen Collection Device (OSCD) has been used in studies for the quantitation of Delta9-tetrahydrocannabinol (THC), but concerns have been raised. In the present study, we investigated whether the volume of oral fluid can be determined and how much THC remains adsorbed on the device. It was found that THC is markedly adsorbed onto the absorptive pad. The recovery using the standard elution procedure was only 37.8 +/- 9.4% for 10 ng/mL and 55.6 +/- 1.0% for 100 ng/mL of THC in oral fluid (n = 5 each). With an additional methanol wash, a further 25% could be eluted. Therefore, a modification of the procedure was evaluated, consisting of the addition of 2 mL of methanol to the elution buffer. THC could be completely recovered over a range of concentrations (1 to 1000 ng/mL). For the determination of the amount of oral fluid absorbed, a gravimetric approach was evaluated as the weights of the devices vary only by 0.6% relative standard deviation. After application of 0.5 mL oral fluid to pads and evaluation of the weight differences, the applied amount could be estimated with a precision of 7.5% (n = 8) and an accuracy of 6.1%. From these results it can be concluded that the OraSure OSCD is useful to collect oral fluid for reliable quantitative THC assay applying a modified elution procedure and gravimetric determination of the amount of oral fluid.

AB - Oral fluid is considered to be an alternative to urine testing for the detection of acute ingestion of drugs. The OraSure Intercept DOA Oral Specimen Collection Device (OSCD) has been used in studies for the quantitation of Delta9-tetrahydrocannabinol (THC), but concerns have been raised. In the present study, we investigated whether the volume of oral fluid can be determined and how much THC remains adsorbed on the device. It was found that THC is markedly adsorbed onto the absorptive pad. The recovery using the standard elution procedure was only 37.8 +/- 9.4% for 10 ng/mL and 55.6 +/- 1.0% for 100 ng/mL of THC in oral fluid (n = 5 each). With an additional methanol wash, a further 25% could be eluted. Therefore, a modification of the procedure was evaluated, consisting of the addition of 2 mL of methanol to the elution buffer. THC could be completely recovered over a range of concentrations (1 to 1000 ng/mL). For the determination of the amount of oral fluid absorbed, a gravimetric approach was evaluated as the weights of the devices vary only by 0.6% relative standard deviation. After application of 0.5 mL oral fluid to pads and evaluation of the weight differences, the applied amount could be estimated with a precision of 7.5% (n = 8) and an accuracy of 6.1%. From these results it can be concluded that the OraSure OSCD is useful to collect oral fluid for reliable quantitative THC assay applying a modified elution procedure and gravimetric determination of the amount of oral fluid.

KW - Humans

KW - Adsorption

KW - Psychotropic Drugs/analysis/chemistry

KW - Saliva/chemistry

KW - Substance Abuse Detection/instrumentation/methods

KW - Tetrahydrocannabinol/analysis/chemistry

KW - Humans

KW - Adsorption

KW - Psychotropic Drugs/analysis/chemistry

KW - Saliva/chemistry

KW - Substance Abuse Detection/instrumentation/methods

KW - Tetrahydrocannabinol/analysis/chemistry

M3 - SCORING: Journal article

VL - 30

SP - 274

EP - 277

JO - J ANAL TOXICOL

JF - J ANAL TOXICOL

SN - 0146-4760

IS - 4

M1 - 4

ER -