Development of a Gas-Tight Syringe Headspace GC-FID Method for the Detection of Ethanol, and a Description of the Legal and Practical Framework for Its Analysis, in Samples of English and Welsh Motorists' Blood and Urine.

Ethanol is the most commonly used recreational drug worldwide. This study describes the development and validation of a headspace gas chromatography flame ionisation detection (HS-GC-FID) method using dual columns and detectors for simultaneous separation and quantitation. The use of a dual-column, dual-detector HS-GC-FID to quantitate ethanol is a common analytical technique in forensic toxicology; however, most analytical systems utilise pressure-balance injection rather than a simplified gas-tight syringe, as per this technique. This study is the first to develop and validate a technique that meets the specifications of the United Kingdom's requirements for road traffic toxicology testing using a Shimadzu GC-2014 gas-tight syringe. The calibration ranged from 10 to 400 mg/100 mL, with a target minimum linearity of r2 > 0.999, using tertiary butanol as the internal standard marker. The method has an expanded uncertainty at 99.73% confidence of 3.64% at 80 mg/100 mL, which is the blood alcohol limit for drink driving in England and Wales. In addition, at 200 mg%­the limit at which a custodial sentence may be imposed on the defendant­the expanded uncertainty was 1.95%. For both the 80 mg% and 200 mg% concentrations, no bias was present in the analytical method. This method displays sufficient separation for other alcohols, such as methanol, isopropanol, acetaldehyde, and acetone. The validation of this technique complies with the recommended laboratory guidelines set out by United Kingdom and Ireland Association of Forensic Toxicologists (UKIAFT), the recently issued Laboratory 51 guidelines by the United Kingdom Accreditation Service (UKAS), and the criteria set out by the California Code of Regulations (CCR), 17 CCR § 1220.1.

Back to the future: Retrograde alcohol calculations an uncertain science.

Retrograde extrapolations, known as back calculations are widely used in forensic toxicology to estimate the blood alcohol concentration of an individual at some prior time. In the UK guidelines have been issued by the United Kingdom and Ireland Association of Forensic Toxicologists) and the Organization of Scientific Area Committees (OSAC) for Forensic Science. However, these guidelines are not fully agreed and open tointerpretation. Alcohol elimination rates have been discussed in numerous publications since Widmark's original data was published. The current guidance from UKIAFT, is to report the most likely back calculated result together with a range of results based on the 95% confidence limit elimination rates (9 to 29 mg/100 mL/hour).The Divisional Court, upheld by the House of Lords, ruled that in order to convict someone for being over the prescribed limit on the basis of any back calculation, the case must be proven beyond reasonable doubt. A 99.73% confidence interval increased to 3 standard deviations at the lower end would provide a greater factual basis for the court and cover alarger proportion of the population, this can be achieved by increasing the elimination range to 8 to 29 mg/100 mL/hour. Retrograde extrapolations also rely on the subject being post absorptive at the prior time. In the UK, back calculations are validif the subject has not eaten or consumed alcohol withinonehour ofthe back calculation time. Where the subject has eatenprior to the back calculation, experts are instructed to consider whether the back calculation is applicable. In Germany and the United States back calculations are not permitted to a time within 2 h after last drink consumed. The 2 h limit would better meet the highest standard of 'beyond reasonable doubt' burden of proof, and should be used. These proposed changes would decrease the uncertainty associated with retrograde calculations carried out by UK toxicologists.

Evaluation and comparison of sensitivity of alcohol biomarkers PEth, EtG and EtPa in civil cases in England 2022-2023.

This study details trends in direct alcohol biomarker concentrations from civil cases within the United Kingdom (UK). Our subject cohort in this study related to family law litigation, where an individual was subject to an alcohol monitoring order by the court. This monitoring was conducted by quantification of alcohol biomarkers Phosphatidlyethanol (PEth) in dried blood spots (DBS) and Ethyl Glucuronide (EtG) and Ethyl Palmitate (EtPa) from hair segments. In total 298 PEth cases predominantly from the South East of England during the period July 2022 to August 2023 were analysed for alcohol biomarkers in DBS and hair. Subjects alcohol intake was classified as abstinence/low alcohol consumption, moderate or excessive alcohol consumption, based on a combination of Society for Hair Testing and PEth Net guidelines. Our results indicate that 33 % of PEth concentrations were consistent with excessive alcohol use (>200 ng/mL DBS), with 36 % consistent with social or moderate alcohol use (20-200 ng/mL DBS). In relation to EtG and EtPa 23 % and 31 % of subjects were classified as excessive alcohol users respectively. This study indicates that DBS sampling of PEth is a more sensitive predictor of alcohol use, in particular, at differentiating between moderate and excessive alcohol use compared to EtG and EtPa testing in hair. The authors suggest that increased frequency in the sampling of PEth in DBS (multiple occasions per month) may provide a more accurate assessment and simplification of the interpretation criteria of alcohol patterns rather than the combined hair testing and DBS sampling that are typically requested by UK courts.

Toxicological Assessment of the Role of Alcohol and Drugs in Drug-Facilitated Sexual Assault Cases in New Zealand.

This report details the toxicology profile of victims of drug-facilitated sexual assault (DFSA) in New Zealand from 2015 to 2018. This study represents all of the toxicology results for DFSA cases in New Zealand during this time period, of which there were 161 cases. Blood and urine samples were screened for legal and illicit drugs in addition to testing for alcohol and correlating alcohol concentration with sampling delay. Our results indicate that increased delay in sampling time resulted in a corresponding decrease in alcohol concentration. In victims who had declared alcohol use but of which none was detected, the average sampling time was 14 hours for blood and 17 hours for urine, which is in excess of the average sampling delay for even the lowest alcohol-positive samples. The most frequently detected alcohol concentration was in the range of 51-80 mg/100 mL for blood and 121-200 mg/100 mL for urine with an average sampling time of 8.5 and 6.5 hours, respectively. We also examined acetone concentrations in alcohol-positive samples, and our results indicate that 82% of blood alcohol-positive samples contained acetone at concentrations between 5 and 10 mg/L and 68% of alcohol-positive urine samples contained acetone at a concentration >20 mg/L. It may be that the nature of sexual assault affects an individual's metabolism of alcohol and results in increased acetone production. Cannabis was the most commonly detected illicit drug, followed by methamphetamine. In relation to medicinal drugs, there was a high usage of antidepressants and antipsychotics, suggesting the victims may have been people of vulnerable personality. Based on case information, it does not appear there are many cases where stupefaction by unknown administration of a drug has occurred, instead loss of consent through voluntary alcohol and drug consumption is more common and poses a greater risk than surreptitious drug administration.

Determination of ethanol in micro-volumes of blood by headspace gas chromatography: Statistical comparison between capillary and venous sampling sites.

Ethanol is the most commonly encountered drug in forensic toxicology, with widespread use throughout society. For this reason, it is important that there are a variety of reliable and robust methods to detect and quantify the content of alcohol in blood samples of suspected drink drivers. A common method of detection is gas chromatography with flame ionisation detector, with a number of sample preparation techniques employed. Typically, venous blood is sampled and used in the analysis. However, there is currently no legal specification in the UK of the blood sample source. This study investigates the use of capillary blood as an alternative to venous blood alongside two different sample volumes: 100 and 10 µL. Venous and capillary blood were collected from volunteers who had consumed alcohol. All blood sampling was carried out one hour after cessation of drinking. The results show a statistically significant difference between venous and capillary samples, with an average difference of 3.38 ± 1.99 mg/100 mL at 100 µL and approximately 4.13 ± 2.42 mg/100 mL at 10 µL, respectively. Predominantly, venous blood was detected at higher concentrations than the corresponding capillary samples. The deviations in alcohol samples between venous and capillary blood are consistent with previous studies. However, our research indicates that capillary blood is a viable matrix to test for alcohol, albeit one that underestimates blood-alcohol content in relation to venous sampling. There was no statistically significant difference between the 100 and 10 µL sample preparation methods on an individual basis, which infers that micro-volumes of alcohol are suitable for forensic blood-alcohol analysis.

Drugged Drivers Blood Concentrations in England and Wales Prior to the Introduction of Per Se Limits.

This report details the blood concentration of drugs found in motorists suspected of driving under the influence of drugs from 2010 to 2012 in England and Wales. This study was carried out as new legislation has come into place, setting fixed blood concentration limits for drugs in motorists. These include a cannabis (Δ9-THC) blood concentration of 2 µg/L, amphetamine 250 µg/L, benzoylecgonine (BZE) 50 µg/L, cocaine 10 µg/L, 6-monoacetylmorphine 5 µg/L, morphine 80 µg/L, diazepam 550 µg/L and methadone 500 µg/L. Samples were screened for opiates, methadone, benzodiazepines, cannabinoids, cocaine, amphetamines and methamphetamine. Cannabinoids were the most prevalent drug group (29.7%) followed by benzodiazepines (22.7%), opiates (18.8%), cocaine (16.3%), amphetamine (7%) and methadone (5.6%). The analytical results are compared with the new per se limits to give a reference of drug concentrations prior to this legislation coming into effect. Our studies show that 64.9% of the cannabis samples, 59.1% of the cocaine samples and 94.6% of the BZE samples would be above the new per se limits set under Section 5a of the Road Traffic Act. In contrast, the medicinal drugs such as benzodiazepines and opiates (morphine) were predominantly detected at concentrations below the new per se limit. Given its medical applications, amphetamines appear to have been grouped with the medicinal type drugs, with our data showing that 25.2% of the amphetamine positive samples would exceed the new specified limit. These data show that samples containing medicinal and prescription drugs are likely to be detected below the new legal limits, while illicit drugs were typically found at concentrations above the new specified limits.