SOFT 2004 Meeting Abstracts - Society of Forensic Toxicologists

F6
A COMPARATIVE EVALUATION OF THE INSTANT-VIEW 5 PANEL TEST CARD WITH
ONTRAK TESTCUP PRO 5: COMPARISON TO GCIMS AND INSTRUMENT SCREENING
WITH ONLINE REAGENTS
David E. Moody'*, Wenfang B. Fangl, David M. Andrenyak ' , Kim S. Monti l , and Chuck Jones 2.
ICenter for Human Toxicology, University of Utah, Salt Lake City, UT 84112, 2 Northwest Toxicology,
Salt Lake City, UT 84124
We have compared the ability of two on-site testing devices, Instant-View Test Card (Alfa Scientific
Designs, Inc., Poway, CA) (I) and OnTrak TesTcup (Roche Diagnostics Corp., Indianapolis, IN) (T) to
discriminate negative from positive urine samples for the following five drug groups: cannabinoids,
cocaine metabolite, opiates, amphetamines and benzodiazepines. Samples for a precision study were
prepared for each device separately due to cutoff and primary antigen differences. A drug-free urine pool
was fortified in a random fashion to contain the primary antigen at seven concentrations (0, 2S, SO, 75, 12S,
ISO and 17S% of cutoff). These stocks were than submitted for GCIMS confirmation and then 10 aJiquots
from each where prepared and assigned random numbers of I-70 for each test device. All drug groups,
except for cannabinoids were within 10% of target and target concentrations were used for the evaluation.
Cannabinoids deviated more than IS% from target. The GCIMS-determined concentrations were used for
cannabinoids; this resulted in samples at 0,62, 80, 102, 136, 158 and 170% of cutoff. Two individuals
tested each sample. None of the °or 2S% (0 or 62% for cannabinoids) cutoffs tested positive with any
device. The results for the rest of the samples can be summarized as follows where for each device we first
list the % of below cutoff samples testing positive and the % of above cutoff samples testing negative:
cannabinoids (1-3.3, 47.5; T-O, 40); benzoylecgonine (1-2S, 8.3; T-16.4, 0); morphine (I-2.5; 21.7; T -10,0);
amphetamines (1-0, 60; T-22.S, 0) and benzodiazepines (I-8.8, \S; T-O, 21.7). Similar data were collected
for an automated immunoassay using Online reagents; the only imprecise result was for cannabinoids at
102% of cutoff where IS% of the samples tested negative. Samples submitted to NWT were used for the
clinical study. Seventy-five samples that recently screened negative were rescreened for the five drug
groups and the fifty with the lowest absorbance readings were selected as negative samples. Positive
samples were selected from actual positives that had reached their disposal date. They were rescreened for
all five drug groups. Those with results> the 75% control in the screening batch were then submitted to
GCIMS confirmation for the particular drug group. Sufficient samples were screened and confirmed to get
at least 45 samples above the device specific cutoff; with many samples near cutoff and some just below
cutoff. As each on-site device will test for all five drug groups simultaneously, this provided::::: ISO
additional samples that were presumptively negative per drug group. Samples were assigned random
numbers, and two individuals tested each sample. Providing results as the percent of device positives when
the GC/MS results (sum of analytes in many case) are