Alcohol markers in hair: an issue of interpretation

Ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs) are metabolites of alcohol that when detected in hair can provide evidence of a person’s drinking behavior. The analysis of these compounds in hair has become commonplace in recent years and has been used as evidence in legal proceedings. Despite the routine use of such toxicological analysis, the correct interpretation of alcohol biomarker hair testing can be complex, and there may be debate as to the significance of the data. This paper considers whether the accepted norm of applying interpretative cut-off values to EtG and FAEE concentrations from hair samples is appropriate, and asks whether Bayesian theory, using a likelihood ratio approach may offer greater insight as to the strength of evidence. In addition to the complexity of result interpretation in this field, the sensitivity of alcohol biomarkers in hair to distinguish low level drinking from abstinence also represents a significant challenge. The use of fingernail EtG testing as an alternative to hair analysis is explored in this paper and it is proposed that fingernails may in theory show a higher uptake of EtG than hair, and thus show potential as a useful alternative matrix to document long-term low to moderate alcohol consumptio

Sample treatment for tissue proteomics in cancer, toxicology, and forensics

Since the birth of proteomics science in the 1990, the number of applications and of sample preparation methods has grown exponentially, making a huge contribution to the knowledge in life science disciplines. Continuous improvements in the sample treatment strategies unlock and reveal the fine details of disease mechanisms, drug potency, and toxicity as well as enable new disciplines to be investigated such as forensic science. This chapter will cover the most recent developments in sample preparation strategies for tissue proteomics in three areas, namely, cancer, toxicology, and forensics, thus also demonstrating breath of application within the domain of health and well-being, pharmaceuticals, and secure societies. In particular, in the area of cancer (human tumor biomarkers), the most efficient and multi-informative proteomic strategies will be covered in relation to the subsequent application of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) and liquid extraction surface analysis (LESA), due to their ability to provide molecular localization of tumor biomarkers albeit with different spatial resolution. With respect to toxicology, methodologies applied in toxicoproteomics will be illustrated with examples from its use in two important areas: the study of drug-induced liver injury (DILI) and studies of effects of chemical and environmental insults on skin, i.e., the effects of irritants, sensitizers, and ionizing radiation. Within this chapter, mainly tissue proteomics sample preparation methods for LC-MS/MS analysis will be discussed as (i) the use of LC-MS/MS is majorly represented in the research efforts of the bioanalytical community in this area and (ii) LC-MS/MS still is the gold standard for quantification studies. Finally, the use of proteomics will also be discussed in forensic science with respect to the information that can be recovered from blood and fingerprint evidence which are commonly encountered at the scene of the crime. The application of proteomic strategies for the analysis of blood and fingerprints is novel and proteomic preparation methods will be reported in relation to the subsequent use of mass spectrometry without any hyphenation. While generally yielding more information, hyphenated methods are often more laborious and time-consuming; since forensic investigations need quick turnaround, without compromising validity of the information, the prospect to develop methods for the application of quick forensic mass spectrometry techniques such as MALDI-MS (in imaging or profiling mode) is of great interest

Methods for the enhancement of fingermarks in blood

Fingermarks formed in or by blood often require specific development techniques. This review examines techniques and materials that may be used to enhance and record fingermarks deposited in blood or fingermarks generated by blood-contaminated papillary ridges. A large number of techniques are presented here and are discussed from a chemical as well as practical perspective. It is concluded that an optimized sequence of techniques targeting both latent (non-bloody) and bloody fingermarks must be applied to detect and enhance the maximum number of marks, and therefore optimize the information content from exhibits that may bear marks in blood. © 2011 Elsevier Ireland Ltd