FORENSIC TOXICOLOGY - Bio Medical Forensics

K39 Determination of Trace Levels of
Benzodiazepine in Urine Using Capillary
Electrochromatography – Time-of-Flight
Mass Spectrometry
Maximilien Blas, PhD*, 10491 Southwest 15 LN, Apartment 211, Miami,
FL 33174 ;and Bruce R. McCord, PhD, Department of Chemistry, Florida
International University, University Park, Miami, FL 33199
The goal of this presentation is to present the benefit of using a monolith
as a stationary phase in separation science and its hyphenation with a mass
spectrometry detection.
This presentation will impact the forensic science community by
providing information regarding the detection of trace level of
benzodiazepines which are common drugs used as tools in drug facilitated
sexual assault (DFSA).
Benzodiazepines are substances with a wide range of therapeutic uses;
suitable for the treatment of sleeplessness, anxiety, increased muscle tone or
epilepsy.
Mainly because they can produce anterograde amnesia, benzodiazepines
are common drugs used as tools in drug facilitated sexual assault
(DFSA). These drugs are comprised of a 1,4– diazepine ring with a benzene
ring fused to carbons 6 and 7 and typically a phenyl group attached to carbon
5. Following an incident of DFSA, benzodiazepines may be present in very
low concentrations. A successful analytical method for the analysis of these
compounds may require detection limits below 10 ng/mL. Thus a highly
sensitive analytical method is required.
This work details a method for the separation and determination of ten
benzodiazepines in urine using capillary electrochromatography–time of
flight mass spectrometry (CEC–MS(TOF)) and an hexyl acrylate-based
porous monolith. The time of flight mass spectrometer proves to be able to
determine exact mass of protonated benzodiazepines to three decimal places.
This high selectivity along with the CEC separation, provides an effective
method for the identification of benzodiazepines. Linearity is satisfactory for
all compounds in the concentration range of 25–500 ng/mL for lorazepam
and 12.5–500 ng/mL for the others. The relative standard deviations are
between 1.4–2.3% for retention times and 1.1–9.2% for relative areas. Using
the monolithic stationary phase, a pre-concentration step is achievable and
permits a 75–140 fold improvement in sensitivity. This strategy allows the
quantification of these drugs down to 1 ng/mL in urine. This method was
used for the analysis of benzodiazepines in spiked urine samples.
Benzodiazepine, Electrochromatography, Mass Spectrometry
K40 Excretion of 11-Hydroxy-Δ 9 -
Tetrahydrocannabinol (11-OH-THC),
and 11-nor-Δ 9 -Tetrahydrocannabinol-
9-Carboxylic Acid (THCCOOH) in Urine
From Chronic Cannabis Users During
Monitored Abstinence
Tsadik Abraham, MS*, Ross H. Lowe, PhD, and Marilyn A. Huestis, PhD,
Chemistry & Drug Metabolism, Intramural Research, National Institute
on Drug Abuse, National Institute of Health, 5500 Nathan Shock Drive,
Baltimore, MD 21224
After attending this presentation, scientists will understand the urinary
excretion of cannabinoids in chronic cannabis users, a population that is
rarely studied due to the difficulty and cost of sequestering individuals for
extended periods of time.
This presentation will impact the forensic science community by demonstrating
how the urinary 11-OH-THC excretion data conducted with heavy
chronic daily cannabis users during monitored abstinence clearly indicate that
11-OH-THC in urine cannot be used to indicate recent cannabis use.
Seven healthy participants (aged 20-35, four males & three females),
who self-reported an extended history of daily cannabis use, provided written
informed consent for this IRB-approved study. Subjects self-reported
chronic daily smoking of between one and five cannabis “blunts” prior to
entering the closed research unit. During the study, all subjects were under
continuous medical surveillance for up to 29 days at the NIDA Intramural
Research Program to prevent self-administration of additional drugs. Each
urine specimen (n = 259) was collected individually ad libidum. Two mL
urine specimens were hydrolyzed by a tandem enzyme (E. coli β-glucuronidase)/alkaline
method, extracted by SPE (Clean Screen ® ZSTHC020
extraction columns, United Chemical Technologies, Bristol, PA), and
derivatized with BSTFA for 30 min at 85 º C. Trimethylsilyl derivatives of
11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC), and 11-nor-Δ9-tetrahy drocannabinol-9-carboxylic acid (THCCOOH) were resolved and quantified
in a 2-dimensional/cryofocusing chromatography system (Agilent 6890
GC/5973MSD) operated in electron impact selected ion monitoring (EI/SIM)
mode. Limit of quantification (LOQ) was 2.5 ng/mL for both analytes. Accuracy
of the method ranged from 87.6% to 102.1%. Intra- and inter-assay
precision, as percent relative standard deviation, were less than 8.6% for both
analytes.
Time of last detection (> LOQ) of 11-OH-THC for all subjects in urine
ranged from 180 – 716 hours (7.5 to 29.8 days). 11-OH-THC maximum
concentrations ranged from 25 – 133 ng/mL (mean 79.7 ± 40.1, median 67
ng/mL). Maximum concentrations of THCCOOH ranged from 117 – 766
ng/mL (mean 455.3 ± 208.3, median 482 ng/mL). All participants also had
THCCOOH positive urine specimens at the LOQ on the last day of residence
between 7.5 to 29.8 days. It also is important to evaluate urinary THCCOOH
concentrations at the 15 ng/mL federally mandated cut off utilized by most
laboratories. Employing the 15 ng/mL cutoff, THCCOOH urine specimens
also were positive throughout residence on the research unit for 7.5 to 29
days.
These data indicate that following chronic cannabis smoking, 11-OH-
THC can be measured in urine for up to 29 days, negating its value as a
urinary biomarker of recent cannabis use.
Cannabinoids, Urine, GC/MS
K41 Gamma-Hydroxybutyrate (GHB) in
Saliva: A GC/MS Method Applicable
to Toxicological and Physical Evidence
Giorgia De Paoli, PhD*, West Virginia University, Oglebay Hall, 1600
University Avenue, Morgantown, WV 26506; and Suzanne C. Bell, PhD,
West Virginia University, Department of Chemistry, PO Box 6045,
Morgantown, WV 26506-6045
The goal of this presentation is to introduce attendees to the potential
use of saliva as an alternative biological matrix and as a tool in GHB
screening analysis and to establish GC/MS as a sensitive analytical technique
for the detection of GHB in saliva.
This presentation will impact the forensic science community by
describing a proposed method for the rapid, selective and accurate
toxicological screening of saliva analysis for forensic purposes. The use of
a surrogate standard provides a quantitative measure of extraction and preparation
efficiency that is matrix specific. The method described here could be
applied to swabs, neat saliva, and possibly physical evidence such as saliva
on drink glasses. Current research is focused on the latter application.
GHB and related compounds have been known for years because of
their illicit use in drug facilitated sexual assault (DFSA) and to a lesser extent,
as party drugs. This problem is exacerbated by GHB’s rapid clearance rate
and short half life of ~30 min. For this reason, it would be useful to develop
a rapid screening analysis from a biological matrix that predictably tracks
107 * Presenting Author