| |
Published:
Journal of Analytical Toxicology,
ISSN 0146-4760,
Volume 26, Number 8, November/December,
pp. 571-574
TECHNICAL NOTE: In Vitro Production of Gamma-Hydroxybutyrate
in Antemortem Urine Samples
Sarah Kerrigan
New Mexico Department of Health, Scientific Laboratory Division, 700 Camino
de Salud NE, Albuquerque, New Mexico 87106
The in vitro production of gamma-hydroxybutyrate (GHB) in antemortem
urine samples was demonstrated over an eight-month period. Positive chemical
ionization-gas chromatography–mass spectrometry (PCI-GC–MS) was
used to detect trace amounts of GHB produced in vitro under certain storage
conditions. Freshly prepared drug-free human urine was stored at 21, 4, and
–20°C in the presence of preservative. Although artifactual production
of GHB occurred more rapidly at elevated temperatures, the presence of an antimicrobial
agent (sodium azide) in the drug-free urine control did not impede GHB production.
The preliminary data suggest that although in vitro production was demonstrated,
the elevations in concentration were nominal and less than 5 mg/L for all conditions
tested over the 244-day period. These preliminary data suggest that urine samples
should be preserved and stored at –20°C to minimize artifactual GHB
production. Most importantly, conditions of storage and preservative should
also be taken into consideration when interpreting GHB results that are close
to the administrative cutoff. In order to establish the distribution of GHB
concentrations in routine forensic case samples, a series of 100 antemortem
urine samples, in which GHB was not suspected, was analyzed. Samples were preserved
with sodium fluoride (1%) and had been stored for up to one year at room temperature.
Although concentrations as high as 7 mg/L were measured in some samples, the
mean and median concentrations were 1.8 mg/L and 1.6 mg/L, respectively. Even
following storage at room temperature for an extended period, more than 95%
of the urine samples contained less than 5 mg/L GHB and 100% contained less
than 10 mg/L. An administrative cutoff of 10 mg/L in antemortem urine was used
for routine antemortem casework.
Reproduction
of editorial content of this journal is prohibited without publisher’s
permission.
This
article is available in its entirety by fax for $40.00 each.
Visa, MasterCard and AMEX accepted.
To
order electronically click here
or call: 847-647-2900 ext. 1323
or fax request to: 847-647-1155.
To order multiple copies click here.
Please indicate JAT
volume and issue along with page numbers. |
|
Home | Subscribe
| Current Issue | Back Issues
| Search | Advertise | Other Publications
| |
