Internal quality control samples for hair testing

Estimation of the time of zolpidem intake and differentiation between consumption and external contamination using MALDI-MSI for investigations on single hair samples

Estimation of drug ingestion time (event time) and distinguishing between drug ingestion and external contamination are important for interpreting hair analysis results in forensics practice. Here, we present a matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) method for in situ analysis of intact hair. We applied a longitudinal cutting method for a single hair to analysis authentic hair samples from a victim of a drug-facilitated sexual assault (DFSA) case and zolpidem-soaked hair. MALDI-MSI showed that zolpidem-positive segments distributed at 4-6 mm or 6-8 mm from the root in three single hairs of a DFSA victim collected 25 days after the event, at concentrations ranging from 0.1 to 5.7 pg mm-1, in agreement with the results from segmental analysis using liquid chromatography tandem mass spectrometry (LC-MS/MS). The estimation of drug intake time was about 20-30 days before sampling, which was consistent with the known time of drug intake. This MALDI-MS method allows imaging analysis of trace substances in a single hair and can realize the intuitive reflection of drug taking time. In addition, zolpidem applied by soaking was mainly distributed on both sides of the longitudinal hair shaft, whereas ingested zolpidem was found only in the middle of the hair shaft of the DFSA victim. The MALDI-MS images of unwashed and washed hair suggested that the amount of externally applied drug was decreased by washing, it was still present on surface layer (cuticle) sides although. Visualization using MALDI-MSI could therefore distinguish between drug ingestion and contamination by reflecting the distribution and deposition site of the drug in hair.

Validation of two LCHRMS methods for large-scale untargeted metabolomics of serum samples: Strategy to establish method fitness-for-purpose

Untargeted metabolomics by LCHRMS is a powerful tool to enhance our knowledge of pathophysiological processes. Whereas validation of a bioanalytical method is customary in most analytical chemistry fields, it is rarely performed for untargeted metabolomics. This study aimed to establish and validate an analytical platform for a long-term, clinical metabolomics study. Sample preparation was performed with an automated liquid handler and four analytical methods were developed and evaluated. The validation study spanned three batches with twelve runs using individual serum samples and various quality control samples. Data was acquired with untargeted acquisition and only metabolites identified at level 1 were evaluated. Validation parameters were set to evaluate key performance metrics relevant for the intended application: reproducibility, repeatability, stability, and identification selectivity, emphasizing dataset intrinsic variance. Concordance of semi-quantitative results between methods was evaluated to identify potential bias. Spearman rank correlation coefficients (rs) were calculated from individual serum samples. Of the four methods tested, two were selected for validation. A total of 47 and 55 metabolites (RPLC-ESI+- and HILIC-ESI--HRMS, respectively) met specified validation criteria. Quality assurance involved system suitability testing, sample release, run release, and batch release. The median repeatability and within-run reproducibility as coefficient of variation% for metabolites that passed validation on RPLC-ESI+- and HILIC-ESI--HRMS were 4.5 and 4.6, and 1.5 and 3.8, respectively. Metabolites that passed validation on RPLC-ESI+-HRMS had a median D-ratio of 1.91, and 89 % showed good signal intensity after ten-fold dilution. The corresponding numbers for metabolites with the HILIC-ESI--HRMS method was 1.45 and 45 %, respectively. The rs median ({range}) for metabolites that passed validation on RPLC-ESI+- was 0.93 (N = 9 {0.69-0.98}) and on HILIC-ESI--HRMS was 0.93 (N = 22 {0.55-1.00}). The validated methods proved fit-for-purpose and the laboratory thus demonstrated its capability to produce reliable results for a large-scale, untargeted metabolomics study. This validation not only bolsters the reliability of the assays but also significantly enhances the impact and credibility of the hypotheses generated from the studies. Therefore, this validation study serves as a benchmark in the documentation of untargeted metabolomics, potentially guiding future endeavors in the field.

Disappearance of codeine, morphine and 6-MAM in hair after cessation of abuse

Research on the determination of drugs of abuse in hair has established that drugs can be detected in hair even long after cessation of use. The purpose of this study was to analyze hair samples from chronic opioid users who were beginning a controlled drug cessation program. The study population (n = 15) is involved in a drug rehabilitation program in Santiago de Compostela, Spain. Over a 6-month period, subjects provided hair samples at 2-month intervals, with the first sample collected on the day they began the program. Codeine, morphine, and 6-MAM were analyzed by GC/MS (LOQ = 0.2 ng/mg). Hair tresses were divided into 1 cm segments and analyzed for all analytes 0-1 cm corresponding to the proximal portion to the scalp Following cessation of opioid use, traces of codeine, morphine, and 6-MAM still remained in the newly growing hair segments for a specified period. After 2 months, still 27 % of the users tested positive, and at 4 months, 20 % were positive but only for 6-MAM. However, after 6 months of abstinence, the results were negative for all analytes.

Concentrations of citalopram and escitalopram in postmortem hair segments

Hair analysis can provide information regarding previous drug intake and use patterns, as the drugs consumed are incorporated into the hair. Therefore, reference values for drugs in hair are valuable in forensic investigations, especially when evaluating drug intake and assessing drug tolerance. The aim of the study was to determine concentrations of citalopram, escitalopram, and their primary metabolites in hair segments from deceased individuals with mental illness. Concentrations in up to six months prior to death were evaluated and compared with the estimated daily doses. Hair samples collected from 47 deceased individuals, were segmented in one to six 1 cm segments, and extracted overnight in medium. The concentrations in hair were quantified via ultra-high-performance liquid chromatography-tandem mass spectrometry. Following this quantification, the extracts were reanalyzed qualitatively using a chiral method to distinguish between citalopram and escitalopram intake. We found hair concentrations (10-90 percentile (perc.)) of citalopram from 0.12 to 67 ng/mg with a median of 8.2 ng/mg (N = 40 individuals, n = 182 segments) and of escitalopram from 0.027 to 7.0 ng/mg with a median of 3.9 ng/mg (N = 4, n = 23). The metabolite-to-drug ratios in hair (10-90 perc.) of citalopram were 0.091-0.57 with a median of 0.30 (N = 39) and of escitalopram were 0.053-0.63 with a median of 0.41 (N = 3). No correlations were found between concentrations in the hair and the estimated daily dose. However, our results indicate higher concentrations in dark hair compared to light hair, given the estimated doses, and thus an influence of hair color on the results. A significant positive correlation was found between the concentration of citalopram in the proximal segment and the blood concentrations. The median R/S-ratio of citalopram in hair was 1.5 and was similar to previously reported ratios in blood. In the present study, we report concentrations of citalopram and escitalopram in postmortem hair and their relation to an estimated daily dose and thus contribute valuable information in forensic investigations.

Evaluation of decontamination procedures for drug testing in undamaged vs damaged hair

INTRODUCTION

Although substances incorporated by ingestion are strongly bound to hair, their loss may occur if aggressive decontamination procedures are applied, especially in highly damaged/porous hair.

AIMS

Evaluation of cleaning procedures using hair samples with different porosity obtained from ethanol or drug users (cocaine, heroin, methamphetamine, methadone, fentanyl, tramadol, diazepam, buprenorphine, dihydrocodeine, citalopram and trazodone). The effect of washing time and multiple wash steps with water and methanol were evaluated.

METHODS

Hair samples (n=16) were selected and evaluated according to: a) the drug pattern consumption, b) available amount, and c) hair porosity (c1 'cosmetic treatment', c2: storage time). Six of them were soaked with an aqueous deuterated analogue solution. The samples were cut in 1 cm segments and homogenized. All hair samples were then decontaminated one or six times with 1.5 mL of water or methanol during 1, 5, 15, 30, 60 and/or 90 min (n=1 to 3/sample, depending on the available amount of hair). Hair extracts were then cleaned up via an SPE or LLE extraction, while the washes were evaporated to dryness. All were thereafter reconstituted and analysed with routine UPLC-MS/MS methods.

RESULTS AND DISCUSSION

Although concentrations of parent drugs and/or metabolites presented a negative trend along the washing time with methanol (up to 80%), the compounds were relatively well retained in hair even after a 90 min wash in most samples. Their retention would depend mostly on the hair nature rather than their physicochemical properties (whether incorporated by ingestion and/or from external contamination). Moreover, parent drugs and/or metabolites were detected in the washes in most samples, and the ratio between hair and washes decreased along the washing time. More than 50% of the deuterated analogues soaked into hair were still present after the different washing steps.

CONCLUSION

Generally, the substances analysed were well retained in hair samples after different washing steps with water or methanol. Losses were observed more frequently for long term stored hair samples, after decontamination with methanol for more than 30 min. Therefore, prolonged or repeated cleaning with methanol should be avoided in general procedures.

Confirmation of Gelsemium elegans poisoning by UHPLC-MS/MS analysis of koumine, gelsemine, and gelsenicine in hair

A sensitive, accurate, simple, and rapid analytical UHPLC-MS/MS method was developed for identification and quantification of koumine, gelsemine, and gelsenicine in human hair. Approximately 10 mg of hair was extracted with methanol by cryogenic grinding. The limits of detection (LODs) ranged from 1 to 5 pg/mg, and the limits of quantitation (LOQs) ranged from 2 to 10 pg/mg. The method was linear over a concentration range from the LOQs to 1000 pg/mg, and the linear correlation (R²) of the calibration curves was above 0.998 for all three analytes. The bias varied from -6.5-13.1%, while the intra- and inter-day precision relative standard deviation (RSD) values were 4.3-12.4% and 3.7-13.2%, respectively. Recoveries ranged from 79.3% to 103.5%, and matrix effects ranged from 74.3% to 105.5%. The described method was used for the quantitative determination of koumine, gelsemine, and gelsenicine in a human hair sample from a Gelsemium elegans poisoning case. The highest concentrations of koumine, gelsemine, and gelsenicine were 27.2, 18.1, and 4.2 pg/mg, respectively, and corresponded to the segment associated with the ingestion period. To our knowledge, this is the first study to describe hair analysis in a G. elegans poisoning case and to provide quantitative toxicological findings.

Determination of amphetamines, ketamine and their metabolites in hair with high-speed grinding and solid-phase microextraction followed by LC-MS

A novel hair sample pre-treatment method based on high-speed grinding and solid-phase microextraction (SPME) had been applied for the determination of amphetamines, ketamine and their metabolites in hair samples by liquid chromatography-mass spectrometry (LC-MS). A 20 mg sample of hair was ground with 2 mL of saturated sodium carbonate solution using a high-efficiency hair grinder with 70 Hz oscillation for 2 min at 4 °C. After centrifuging, 1.5 mL of the supernatant was transferred and treated with SPME by direct immersion (DI-SPME). The target analytes extracted by fibre were desorbed and analysed using LC-MS. Under the optimum conditions, a recovery of 90.2%–95.8% was obtained for all analytes. The analytical method was linear for all analytes in the range from 0.2 to 10 ng/mg with the correlation coefficient ranging from 0.9985 to 0.9993. The detection limits for all analytes were estimated to be 0.067 ng/mg. The accuracy (mean relative error) was within ±6.9% and the precision (relative standard error) was less than 6.8%. The combination of high-speed grinding of hair and SPME had the advantages of being easy to perform, environment-friendly and high in detection sensitivity. The proposed method offered an alternative analytical approach for the sensitive detection of drugs in hair samples for forensic purposes.

Key Points

The SPME was involved for the determination of drugs in hair with LC-MS.

The hair high-speed grinding combined with SPME was firstly developed.

Good linearity, sensitivity, recovery and precision were achieved.

Detection of amfepramone and its metabolite cathinone in human hair: Application to a uthentic cases of amfepramone use

In recent years, overseas anti-obesity drugs including amfepramone have flowed into China through the internet or personal import by travelers. Amfepramone is controlled in China and is not available as a pharmaceutical product. It is obtainable either through the internet or imported by individuals across the border. The abuse of amfepramone is causing serious health problems. A method for the detection and quantification of amfepramone and its metabolite cathinone in human hair was developed and fully validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Approximately 10 mg of hair was weighed and pulverized with extraction solvent (a mixture of methanol: acetonitrile: 2 mM ammonium formate [pH 5.3] [25:29:46, v/v/v]). The limit of detection (LOD) and the limit of quantitation (LOQ) were 5 and 10 pg/mg, respectively. The method was linear over a concentration range from 10 to 10,000 pg/mg. The accuracy varied from -9.3% to 2.3%, with acceptable intra- and inter-day precision. The validated method was successfully applied to 17 authentic cases. The amfepramone concentrations ranged from 11.7 to 209 pg/mg, with a median of 30.2 pg/mg, and the hair cathinone concentrations ranged from 11.9 to 507 pg/mg, with a median of 54.0 pg/mg. This is the first report of amfepramone concentrations in human hair from amfepramone users. Cathinone can be incorporated into hair after amfepramone use.

Segmental hair analysis for flunitrazepam and 7-aminoflunitrazepam in users: a comparison to existing literature

The availability of more quantitative data on flunitrazepam (FLU) and 7-aminoflunitrazepam (7AF) would aid in obtaining a better understanding of the interpretation of FLU concentrations in human hair. The purpose of this study was to provide concentrations of FLU and 7AF in hair segments of 22 FLU users. Quantitative data regarding hair concentrations of FLU and 7AF from various types of cases were also reviewed to give a comprehensive overview of the comparability of different studies. Three to six 1 cm segments of scalp hair from 22 FLU users were analyzed by a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method. FLU and its metabolite were confirmed in the hair segments from all cases. Concentrations of FLU and 7AF in the segments ranged from 0.01–0.16 ng/mg (median of 0.03) and 0.01–0.34 ng/mg (median of 0.09), respectively. Most cases had FLU and 7AF distributions along the hair segments that were suggestive of repeated drug use. A summary of the published concentrations gives valuable data and can assist forensic investigators in their estimations of drug use history and patterns.

Key points

A method using LC–MS/MS to quantify flunitrazepam and its metabolite was described.

Segmental analysis of flunitrazepam and its metabolite in human hair was reported.

A comprehensive overview of quantitative data was given.