Evaluation of Oral Fluid Testing Devices

摘要

Oral fluid (saliva) testing is becoming increasingly popular as a means for quickly determining if someone might be under the influence of drugsor alcohol. Collection of saliva specimens is noninvasive, compared to blood and nonintrusive with regards to the privacy of the subject when compared to urine collection. In addition, no special facilities or training are required in order to obtain the saliva specimen and supervised sample collection eliminates the possibility of sample adulteration. Drug detection is possible within a few hours to a full day from initial use, a timeframe similar to blood samples. The market for these tests is dominated by small, single use devices. For drugs of abuse testing, the instructions include a disclaimer that a positive usetest must be confirmed by more rigorous laboratory tests. NIST undertooka study of oral fluid testing devices for detecting alcohol (ethanol) and for detecting common drugs of abuse. This report provides details ofthe two studies. Five devices intended for detecting alcohol in oral fluid were evaluated in terms of their accuracy in detecting varying levels of ethanol in oral fluid. The ability of the devices to reliably detect ethanol in the presence of potential interfering substances was also assessed. Four point-of-collection (POC) devices for detection of drugs of abuse in oral fluid were also studied. The ability of the devices to meet the manufacturers claims and their practical applicationto detection of drugs of abuse at low concentrations in oral fluid were evaluated. Human saliva fortified with known quantities of cocaine, phencyclidine (PCP), codeine, morphine, amphetamine, methamphetamine, and (-)-11-nor-9-carboxy- .9-tetrahydrocannabinol (carboxy-THC), was usedin the analysis. Each device was also tested for cross-reactivity with anumber of common orally administered, over the counter medications, as well as substances which could be expected to occur in human saliva. In general, the POC devices performed close to their specifications, with afew exceptions. In some cases, the design of the device could make interpretation of the results unreliable or uncertain.