The evaluation of screening and verification methods used in saliva, urine, blood samples in the drugs analysis in terms of laboratory and clinical view

Substance abuse causes significant psychological, economic and sociological problems in the individual and society. Article 191 of the Turkish Penal Code states that the use of drugs/stimulants is prohibited and that if the treatment or probation measure is not followed, it will be punishable by imprisonment from two to five years. Therefore, it is very important that the drugs/stimulants are identified correctly and precisely. Immunological methods are used for screening drugs/stimulants, chromatography and mass spectrometry are used for verification. The treatment of individuals with substance use disorder or who have been subjected to Probation measure is carried out in AMATEM clinics and the individuals' urine samples are screened by immunoassays. On the other hand, cannabis, heroin, cocaine, amphetamine and benzodiazepines are screened in saliva with the help of POCT device to assess whether the individual is driving under the influence of drugs/stimulants in the saliva. Positive screening results obtained from these immune methods are confirmed by LC-MS/MS method in Forensic Medicine institutions if necessary. The safety of the POCT method used in traffic drug screening and the immune method used in AMATEM clinic was tested for the first time in this study. The results of these two screening methods used in our country were confirmed by LC-MS/MS device in plasma and urine samples by using commercial kit and laboratory developed method. In our study, significant data were obtained in terms of POCT device which is in trial phase in traffic application and needed to be used in probation institutions. The specificity of our POCT device was found to be high, but the sensitivity was good for heroin, cocaine and amphetamines, insufficient for MDMA/methamphetamine, and because of the positive results in the saliva test for benzodiazepines and cannabis, the sensitivity could not be calculated. It is observed that the immune method used in AMATEM clinic has sufficient sensitivity in accordance with its purpose and it should be considered that there may be specificity problems due to cross reaction. When the cut-off limit of the immunostaining method used in AMATEM was used as 2000 ng/mL, as suggested by SAMHSA instead of 300 ng/mL for opiates, the specificity of the method increased from 83% to 95%. It is therefore recommended to use a cut-off limit of 2000 ng/mL for opiates to reduce false positive results and the number of samples leading to validation. In our study, validation methods of urine and blood samples LC-MS/MS validation parameters developed in the commercial kit and laboratory were compared and calculated. Our study also contains meaningful data in terms of many parameters that may cause differences such as ionization mode, extraction method and standards used in LC-MS/MS methods. As a result, it is important to keep in mind that the positive or negative result given in the drugs/stimulant analysis is part of the judicial process leading to the arrest of the person. As well as validation and verification of the analyzes performed at the analytical stage, it is essential to evaluate the effect of the usage time and the type of the sample on the result by knowing the results accordingly. In addition, it is necessary to develop specific POCT devices and to evaluate the performance of each device developed. Key words: substance-related disorders, method comparison, POCT testing, immune method, LC-MS/MS method