Abstract
Forensic toxicology entails the analysis of stains and drugs found in fluids and solid materials collected from a crime scene. Numerous methods are used in a toxicological analysis. Currently, scientists use Quick Kits in analyzing drugs in tissues obtained from both living and dead organisms. Also, forensic science uses an approach that focuses on postmortem fentanyl examinations in human fatalities.
In a bid to achieve accurate results, forensic scientists have to handle the specimens with great care. Besides, they need to posses clear knowledge of the duration that the specimen has taken since the crime occurred. Sealing and labeling specimens help in protecting them from contamination during the analysis process. The main challenge that affects the credibility of results is the lack of data that can act as guidance to the scientists.
Criminalism and Forensic toxicology
Biological stains present at crime scenes can facilitate in identifying the victim, cause of the crime, or who committed the crime. On the other hand, toxicology may reinforce the investigation. For instance, investigators may use toxic materials to compel a criminal to give an account of his crime (Castello, 2009). It becomes hard to distinguish between recent and older stains. Besides, temperature changes affect the stains making it hard for pharmacologists to obtain accurate results in stain analysis.
Currently, forensic scientists use Quick Kits to establish the existence of particular drugs in blood and urine. As long as the specimens are well preserved, the kits may help in analyzing drugs in liquids obtained from dead or living tissue (Castello, 2009). The only challenge is that no information documenting this method currently exists. Hence, it might be hard for forensic scientists to determine the correct procedure of carrying out the analysis using Quick Kits.
Forensic toxicology practices
Forensic toxicologists carry out investigations on murders, suicides, and accidental poisonings. In 2009, 4.8 percent of deaths in the United States were due to accidental deaths. Accidental deaths come in the form of accidental overdoses. Numerous cases of accidental poisoning happen in hospitals without the knowledge of medical professionals (Kochaneck et al., 2009).
The forensic toxicology practice demands the detection and quantification of the particular compounds. The preliminary investigation starts with a screening test. If the screening turns out positive for numerous drugs, the toxicologist is required to go further to determine and quantify the particular compounds. Since some compounds cannot endure the temperature required for gas chromatography, the toxicologist uses alternative methods in the analysis (Kochaneck et al., 2009). Regardless of the forensic method used, the toxicologist has to abide by the established legal procedures for the outcomes to be acceptable in court.
Postmortem toxicology examination is different from hospital examinations concerning the samples used. Urine and blood are the main samples collected during an investigation. However, urine may not be available for postmortem, thus prompting toxicologists to use solid organs like liver, vitreous humor, and brain (Kochaneck et al., 2009).
At times, the testing calls for unique approaches. For instance, once a person dies, cocaine concentration in the blood decreases, gradually calling for special approaches to detect it. Consequently, to get accurate information, toxicologists ought to be equipped with numerous skills in forensic investigation.
Identifying toxicological evidence in forensic pharmacology
Courts use varied standards of evidence for varied circumstances. In a bid to come up with correct results in forensic pharmacology, it is imperative to have ideas regarding the duration when the sample is taken relative to the time when the incidence happened (Ferner, 2012). Blood samples used in the analysis may need anticoagulants or preservatives to guarantee accurate results.
Therefore, to avoid gross errors, it is advisable not to measure serum lithium concentrations after putting the blood into lithium heparin tubes. Another major challenge encountered during forensic analyses are sample identification. The major difficulties during analysis emanate from both false positive and false negative results (Ferner, 2012). Also, samples may be tainted during handling. Consequently, for a criminal conviction to be successful, the involved investigators should be exceedingly careful.
The concentration of drug in the blood changes with time after a victim’s death (Ferner, 2012). The variation is partly due to changes in temperature and level of putrefaction. Post-mortem redistribution makes it hard for technicians to come up with correct results. Thus, to obtain accurate results, researchers focus on drug concentration in various sampling sites like the heart and compare it with that of blood taken from another part of the body.
The ration between the two gives the magnitude of redistribution. Once a researcher is satisfied with the collected sample, he or she conducts the analysis and compares the results with the clinical data. If the data matches, then one may relay the results to the relevant people (Ferner, 2012).
Collection of samples
The first step in the sampling procedure entails labeling the sampling containers. Labeling facilitates in ensuring that individuals handling samples do not mix them. Without labeling the sampling containers, it is possible for the entire procedure to be compromised (Dinis-Oliver et al., 2010). The labels carry information about the request number, the victim’s name, type of sample, the collector’s name, and date of collection.
Every sample is assigned a unique identification number to ensure that the researcher does not confuse it. The purpose of the investigation dictates on the sample container to use (Dinis-Oliver et al., 2010). Sample containers ought to facilitate in the maintenance of the analyte and ensure that the sample is not contaminated. Once the sample is obtained, one should fill a forensic toxicology request. The request form facilitates the process of sample analysis.
Toxicological judgment depends on the reliability of the toxicological analysis. Unreliable results may lead to wrong conclusions, thus making a court to issue wrong judgments. Based on the duration that a specimen takes before analysis, the toxin concentration may change significantly (Dinis-Oliver et al., 2010).
Hence, if the specimen is not being analyzed immediately, it has to be stored under the correct temperature and ensure the use of appropriate preservatives. At times, transportation and storage of a sample after analysis may call for the same precautions. Currently, there are no clear guidelines on how to preserve specimens. Nevertheless, it is advisable to use well-filled and tightly covered containers (Dinis-Oliver et al., 2010).
Fentanyl in postmortem forensic toxicology
Analysis of postmortem drug concentration is a taxing job. Since it is hard to employ a randomized study of postmortem drug concentration on human beings, forensic science depends on animal data and other information gathered from case series (Palmer, 2010). Nevertheless, this approach may not help in making accurate conclusions.
Therefore, to solve this challenge, forensic science uses an approach that focuses on postmortem fentanyl examinations in human fatalities. Fentanyl is a drug that is administered either percutaneously or through inhalation. A postmortem procedure may be executed using intravenous (IV) fentanyl or transdermal (TD) fentanyl (Palmer, 2010). Hospitals and courts regularly receive reports on suicides and accidental deaths from overdose of injectable fentanyl.
Toxicity and death from fentanyl intoxication with TD fentanyl patches because of patch overuse, as well as inappropriate use of patches, placing patches on inappropriate anatomic sites, inhaling the contents of the patch, chewing or eating patches and drinking the contents of the patch steeped as tea, has been reported (Palmer, 2010, p.775).
In spite of individual case reports offering extra data, which could be of great help for correct interpretations, the majority of investigations involving postmortem performance of fentanyl require further investigations. In 2000, 25 autopsy cases indicated that the victims suffered from fentanyl overdose (Palmer, 2010). Pathologists claimed that there were traces of fentanyl in the blood taken from the hearts of the victims. Despite the results, it was learned that with curative administration, the anticipated postmortem blood fentanyl level normally surpasses the level recorded in kinetic examinations of living human beings.
Forensic scientists encounter challenges when interpreting postmortem fentanyl data. Before coming up with a conclusion, scientists consider factors like drug tolerance, concomitant medications, basic pathology, and other postmortem data (Palmer, 2010). Nevertheless, the available information that could facilitate in analyzing a postmortem does not cover these factors comprehensively. Hence, scientists lack a reference when carrying out their postmortem analyses. Lack of adequate postmortem fentanyl data makes it hard for forensic scientists to make a conclusive decision about the cause of deaths of most victims.
References
Castello, A., Navarro, E., Banon, R., & Verdu, F. (2009). A crossroad between criminals and forensic toxicology. Internet Journal of Forensic Science, 4(1), 1-7.
Dinis-Oliver, R., Cavalho, F., Duarte, J. A., Remiao, F., Marques, A., Santos, A., & Magalhaes, T. (2010). Collection of biological samples in forensic toxicology. Toxicology Mechanisms and Methods, 20(7): 363-414.
Ferner, R. (2012). Toxicological evidence in forensic pharmacology. The International Journal of Risk & Safety in Medicine, 24(1), 13-21.
Kochaneck, D., Xu, Q., Murphy, L., Minino, M., & Kung, H. (2009). Preliminary data for 2009: National vital statistics. Hyattsville, MD: National Center for Health.
Palmer, R. (2010). Fentanyl in postmortem forensic toxicology. Clinical toxicology, 48(8), 771-784.