FORENSIC TOXICOLOGY - Bio Medical Forensics

K15 Postmortem Production of Ethanol in
Different Tissues Under Controlled
Experimental Conditions
Stojan Petkovic, MD, MSc*, Milan Simic, MD, PhD, and Djura
Vujic, BSc, Department of Forensic Medicine, Clinical Center Novi
Sad, Hajduk Veljkova 5-7, Novi Sad 21000, Serbia and Montenegro
After attending this presentation, attendees would be able to establish
the level of postmortem ethanol (produced after death) under controlled
experimental conditions within different time intervals and under different
temperature.
The authors would like to see the results from this survey considered
as a basis for further investigations with crucial aim that is very important
in forensic practice - to distinguish postmortem (endogenous) production
of ethanol versus ethanol ingestion before death (exogenous one).
There is the assumption that postmortem production of ethanol is in
accordance with temperature increase, duration of time interval, and
amount of carbohydrates in the tissue.
All the activities of this survey were performed at the Department of
Forensic Medicine, Clinical Center Novi Sad, on the corpses of persons of
both sexes, aged between 20 and 50 years, whose death occurred 6-12
hours before autopsy, i.e., taking the specimen. The death of the persons
whose corpses were used for the analyses was of natural or violent origin
and it excluded medical interventions (treatment and death in the hospital,
or other medical institution), and the violent deaths caused by toxic substances.
The specimen of blood, liver, skeletal muscle and kidney were
taken from 30 corpses and were divided into 2 control and 3 experimental
groups. The first control group of specimen was analyzed immediately
after taking, and the second control group of specimen was stored at the
temperature of – 20 ºC. The first experimental group of specimen was
stored at the temperature of + 4 ºC, the second at +20 ºC, and the third one
at +30 ºC. All experimental groups were divided into four subgroups,
according to the duration of incubation at given temperature: the first subgroup
was stored at appropriate temperature for 24 hours, the second for
48 hours, the third for 96 hours and fourth one, for 192 hours. Chemical
ethanol analysis of the taken specimen was performed by standard gaschromatography
method.
The results show that all of the control specimen stored at -20 ºC do
not show any change in ethanol quantity, in all time intervals. There is no
statistical significance of ethanol quantity change remarked in any tissue
stored at +4 ºC at any time interval. At the temperature of +20 ºC, all
tissues, except blood, show statistically significant ethanol quantity
change referring to time intervals, comparing with controls. The postmortem
production of ethanol at +30 ºC is increased due to the course of
time, in all tissues. Statistically significant ethanol quantity change appears
on the 1st day (kidney, muscle and liver tissue) and 2nd day (blood) at +30
ºC, while at +20 ºC it appears predominantly on the 2nd day (kidney, liver
and muscle tissue). Significant increase of produced ethanol in liver,
kidney and muscle tissue at +30 ºC is noted up to particular time interval
(liver – 4th, kidney and blood – 2nd, muscle 1st day), after which these
levels are mildly decreased without statistical significance, except in blood
tissue, where the significant decrease was found. The absolute range of
produced ethanol reaches the highest level in liver tissue.
On the basis of the results gained during this survey, we can confirm
the assumptions as follows: 1. the postmortem production of ethanol
occurs and it varies in different tissues; 2. postmortem production of
ethanol is increased by rise in temperature; 3. postmortem production of
ethanol depends on the tissue amount of carbohydrates (liver – glycogen);
4. postmortem production of ethanol is increased, in general, in accordance
with the course of time. It is observed, too, that postmortem production
of ethanol is increased up to particular time interval at +30 ºC,
after which the values of measured ethanol are mildly decreased.
Postmortem Production, Ethanol, Experimental Conditions
* Presenting Author
K16 The Measurement of Uncertainty
for Toluene Analysis in Biological
Fluids by HS-GC
Sang-Cheol Heo, MS, Ji-Sook Min, PhD, Jong-Seo Park, MS, Mi-Ae
Lim, Eun-Ho Kim, Ji-Sook Min, PhD, Sung-Woo Park*, National
Institute of Scientific Investigation, 331-1 Sinwol7-dong Yangcheon-ku,
Seoul 158-707 Korea
After attending this presentation, attendees will understand the
uncertainty estimation process and to validate the method in forensic
field.
Toluene has been widely used as an industrial solvent. Sniffing of
thinners or adhesives containing toluene, which is illegal in Korea, is
known to occur. The determination of toluene level in biological fluids
such as blood and urine is a powerful tool for monitoring toluene
exposure and for evaluation of toluene inhalation. The aim of this work
was to validate the method of toluene determination and obtain the
uncertainty estimate around cut-off level. The chromatographic conditions
of the method employ an HP INNOwax capillary column (30m x
0.25mm, film thickness 0.25um), programmed condition ( 60 ºC(6min),
10 ºC/min, 140 ºC(3min)) with He at a column flow of 1.0ml/min,
injector and detector temperature at 240 ºC, a split ratio of 30:1. Sealed
sample vials containing biological sample 1ml, buffer 2ml and isobutanol
50ul as an internal standard were heated at 60 ºC for 20 minutes
in headspace autosampler and injected into GC with FID. The linearity
of the toluene peak area responses was demonstrated from 0.05ppm to
100ppm. Repeatability and reproducibility of the toluene peak area
responses showed R.S.D. of 3.6% and 4.6 %, respectively. The limits of
detection and quantitation were determined to be 0.01ug/mL and
0.02ug/mL in water and 0.02ug/mL and 0.05ug/mL in urine, respectively.
The other parameters such as selectivity, sensitivity, accuracy and
recovery were also examined. The measurement uncertainty for toluene
analysis was estimated from experimental results. We determined
0.068ug/mL as the uncertainty for cut-off level, 0.1ug/mL.
Toluene, Uncertainty, Validation
K17 Comparison of Calibration Approaches
for the Quantitative GC/MS Analysis
on Secobarbital
Wei-Tun Chang, PhD*, Central Police University, 56 Shujen Road,
Kueishan,Taoyuan 333, Taiwan, ROC; Yi-Hung Wu, MS, Forensic
Science Center, Kaohsiung Municipal Police Department, Kaohsiung,
Taiwan, ROC; Guang-Ming Xu, MS, Department of Forensic Science,
Central Police University, Taoyuan, Taiwan, ROC; Chin-Thin
Wang, PhD, St. John’s & St. Mary’s, Institute of Technology, Taipei,
Taiwan, ROC; Yang-Hung Liang, MS, Tri-Service General Hospital,
Taipei, Taiwan, ROC
After attending this presentation, attendees will be familiar with the
characteristics of the calibration curves resulting from the use of isotopic
analogs of the analyte as the internal standards (ISs). Specific parameters
studied include (a) ion cross-contribution and (b) column temperature
programming conditions that may affect the use of calibration
approaches.
This study was placed on practically evaluating the calibration
approach by using 2H- and 13C-analogs as ISs for the quantitative determination
by GC/MS in urine. An automatic well-established solid-phase
extraction and methylation procedures were used prior to the GC/MS
measurement. The cross-contribution of ions designated for the analyte
and its IS were evaluated by the “direct normalized measurement”
method through selected ion monitoring (SIM) mode. The spiked IS
magnitude and reconstitute volume were also evaluated for the appro-
210