A large number of various narcotic drugs can, in small but well-defined doses, be deposited on hair sections. Such an analysis will help to identify even a single small drug use a couple of months before the examination. This technique (namely, the detection of drugs by hair analysis) is highly effective and is used in the developed countries of Europe and the USA. The analysis is used in many companies, firms and clinics to monitor the use of drugs by employees or patients.
Characteristics of the procedure
When conducting a hair analysis for drug use, you can identify how long ago and what drugs were used. During this procedure, it is permissible to take hair samples even several months after the drug with narcotic characteristics was consumed by the subject. With a high degree of probability and accuracy, specialists will be able to answer questions about when exactly, what exactly and in what quantity the subject used. In forensic science, hair analysis for drugs is used to establish the fact of drug addiction in the deceased.
The biological basis for the accumulation of drug traces in the hair can be explained quite simply. When ingested, the drug is absorbed, and its particles enter the circulatory system. Every hair on the human body has the ability to absorb substances from the blood. When narcotic substances enter the hair, they begin to accumulate.
Among the main advantages of the technique for determining drug addiction by a hair cut, experts name the exact probability of using these substances, even if there was a single case in the last few months. Also, the advantages include the ability of specialists to distinguish between single and chronic drug use by a person, a high level of reliability of the results obtained, and the ease of taking samples for research.
The timing of drug use can also be determined by the process of hair regrowth. Their growth rate is from 1 to 1,2 centimeters per month. At the same time, all the substances taken by a person during a given period are recorded on the regrown length, as on a magnetic tape. So, for example, when examining a three-centimeter examined exhibit, the first centimeter from the root contains data on all the substances that the patient has taken over the past month. The second centimeter will show a similar picture of the previous month, and the third will tell you what the person took 3 months ago. This principle is also applied to detect drug use over a longer period of time. With the help of a three-centimeter hair, conclusions can also be drawn about the single use of any substances over a three-month period.
The maximum duration of a drug test will depend solely on the length of the hair in question. The most accurate results are obtained from samples taken from the human head, however, samples can be obtained from other areas for research. It is simply necessary to keep in mind that the hair in the armpits, on the limbs and other areas does not grow back so intensively, and, therefore, may distort the obtained information about the relative period. The only reliable fact in such an analysis will be the fact of using or not using drugs in general.
Selection of survey units and analysis
For analysis for the presence of narcotic substances, the hair is taken in a bun on the head. There should be about a hundred of them, and they are cut with scissors as close to the scalp as possible. Sometimes, if necessary, additional samples can be taken from other parts of the subject’s body. Each sample is placed in a separate envelope, which is then carefully sealed. When forwarding, copies are usually first put into a file, and only after that into an envelope.
Upon receipt of envelopes with hair in special institutions, they are assigned a serial number and sent directly to the laboratory for examination. The test sample is placed in a test tube and treated with a special solvent with an organic base to dissolve the protein hair shaft and release the substances that have been accumulated. The solution is then analyzed using a modern gas chromatograph or mass spectrometer, the accuracy of which makes it possible to detect the substances of interest with a high degree of probability and accuracy.
On a mass spectrometer or gas chromatograph, substances such as heroin, cocaine, marijuana, methadone, diphenhydramine, nicotine, methamphetamine and many others can be detected. During this procedure, even rare drugs are detected. Specialists are constantly developing new methods for detecting other, updated drugs of narcotic effects.
In modern conditions, hair analysis for drugs is one of the most effective and accurate ways to determine such substances in the human body. All other drug detection methods can only tell about the group of substances contained in the blood (opiates, for example), without specifying the specific substance and the timing of its use. This creates difficulties, since other methods cannot differentiate cocaine from codeine – a component of many antitussive or antipyretic drugs. Thus, GC/MS analyzes (gas chromatograph or mass spectrometer) is the most preferred and highly informative in this matter.