Development of an UPLC–MS/MS method for the analysis of 16 synthetic opioids in segmented hair, and evaluation of the polydrug history in fentanyl analogue users

Development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method including 25 novel synthetic opioids in hair and subsequent analysis of a Swiss opioid consumer cohort

Major public health concern is raised by the evidence that common drugs like heroin are now frequently laced or replaced with highly potent novel synthetic opioids (NSOs). The objective of this study was to explore the prevalence and patterns of NSOs in a cohort of Swiss opioid users by hair analysis. Hair analysis is considered an ideal tool for retrospective consumption monitoring. Hair samples from 439 opioid users in Zurich were analyzed. Study inclusion required a previous positive hair test result for heroin metabolites, oxycodone, fentanyl, methadone, or tramadol. The samples were extracted with a two-step extraction procedure, followed by a targeted LC-MS/MS (QTRAP® 6500+) analysis in multiple reaction monitoring mode for a total of 25 NSOs. The method underwent full validation and demonstrated good selectivity and sensitivity with limits of detection (LOD) as low as 0.1 pg/mg. The analyzed sample cohort demonstrated a positivity rate for NSOs of 2.5%, including the following NSOs: butyrylfentanyl, acrylfentanyl, furanylfentanyl, methoxyacetylfentanyl, ocfentanil, U-47700, isobutyrylfentanyl and benzylfentanyl. Furthermore, we were able to identify specific consumption patterns among drug users. The results indicate that hair analysis is a valuable tool for investigating the prevalence of NSOs in drug-using populations, which seems to be low in the case of Swiss opioid users. Nevertheless, the results highlight the need for sensitive analytical detection methods in forensic toxicology to identify and monitor substance distribution in different populations.

Are the NPS commonly used? An extensive investigation in Northern Italy based on hair analysis

New psychoactive substances (NPS) are present on the Italian illicit markets, but data from the analysis of biological samples to evaluate their real consumption are rare. For this reason, an epidemiological study was carried out by means of a ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method for the determination of 115 NPS on the keratin matrix. A total of 847 hair samples were collected in 2020 and 2021 and analyzed. The sample donors were in the age range of 18-40 years, from both genders, and were tested either for driving relicensing or for drug withdrawal monitoring. The UPLC-MS-MS system consisted of a Waters ACQUITY UPLC® I-Class, coupled with a Waters XEVO TQ-XS triple quadrupole mass spectrometer. The method was developed and fully validated according to international guidelines. Limits of detection were set as the minimum criterion to identify positive samples. Overall, 56 samples resulted positive for ketamine, 35 for norketamine, 6 for fentanyl, 3 for norfentanyl, 3 for 4-ANPP, 3 for MDMB-4en-PINACA, 2 for N,N-DMT, 2 for 5-chloro AB-PINACA, 1 for α-PHP and 1 for methcathinone. NPS were detected in a small part of samples (8.4%), which seems in contrast with their apparent wide diffusion in Italy, yet it is congruent with similar investigations based on hair analysis. Future studies will be performed to expand the investigated population, especially in terms of age and origin.

Review of analytical methods for screening and quantification of fentanyl analogs and novel synthetic opioids in biological specimens

Fentanyl, fentanyl analogs, and other novel synthetic opioids (NSO), including nitazene analogs, prevail in forensic toxicology casework. Analytical methods for identifying these drugs in biological specimens need to be robust, sensitive, and specific. Isomers, new analogs, and slight differences in structural modifications necessitate the use of high-resolution mass spectrometry (HRMS), especially as a non-targeted screening method designed to detect newly emerging drugs. Traditional forensic toxicology workflows, such as immunoassay and gas chromatography mass spectrometry (GC-MS), are generally not sensitive enough for detection of NSOs due to observed low (sub-μg/L) concentrations. For this review, the authors tabulated, reviewed, and summarized analytical methods from 2010-2022 for screening and quantification of fentanyl analogs and other NSOs in biological specimens using a variety of different instruments and sample preparation approaches. Limits of detection or quantification for 105 methods were included and compared to published standards and guidelines for suggested scope and sensitivity in forensic toxicology casework. Methods were summarized by instrument for screening and quantitative methods for fentanyl analogs and for nitazenes and other NSO. Toxicological testing for fentanyl analogs and NSOs is increasingly and most commonly being conducted using a variety of liquid chromatography mass spectrometry (LC-MS)-based techniques. Most of the recent analytical methods reviewed exhibited limits of detection well below 1 μg/L to detect low concentrations of increasingly potent drugs. In addition, it was observed that most newly developed methods are now using smaller sample volumes which is achievable due to the sensitivity increase gained by new technology and new instrumentation.

Detection of fentanyl, synthetic opioids, and ketamine in hair specimens from purposive samples of American and Italian populations

With the current crisis related to the diffusion of fentanyl and other novel opioids in several countries and populations, new and effective approaches are needed to better elucidate the phenomenon. In this context, hair testing offers a unique perspective in the investigation of drug consumption, producing useful information in terms of exposure to psychoactive substances. In this research, we applied targeted ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analytical methods to detect novel synthetic and prescription opioids and other common controlled psychoactive drugs in the keratin matrix. A total of 120 hair samples were analyzed from the United States (US) and Italy, segmented when longer than 6 cm, and then analyzed. In the 60 samples (83 segments in total) analyzed from a purposive sample of data collected in the US, fentanyl was detected in 14 cases (16.9%), with no detection of nitazens or brorphine. We also detected fentanyl metabolites, despropionyl-p-fluorofentanyl, and prescription opioids. In the 60 samples collected in Italy (91 segments in total), ketamine was the most prevalent compound detected (in 41 cases; 45.1%), with ketamine demonstrating a strong correlation with detection of amphetamines and MDMA, likely due to co-use of these substances in recreational contexts. Several common drugs were also detected but no exposure to fentanyl or its analogs were detected. Results of this retrospective exploration of drug use add to increasing evidence that hair testing can serve as a useful adjunct to epidemiology studies that seek to determine biologically confirmed use and exposure in high-risk populations.

Non-fentanyl new synthetic opioids - An update

BACKGROUND

New synthetic opioids (NSO) constitute one of the fastest-growing group of New Psychoactive Substances, which emerged on the illicit drug marker in the second half of 2000's. The most popular and the largest NSO subgroup are high potency fentanyl and its analogs. Subsequent to core-structure scheduling of fentanyl-related substances many opioids with different chemical structures are now emerging on the illicit drug market, rendering the landscape highly complex and dynamic.

METHODS

PubMed, Scopus and Google Scholar were searched for appropriate articles up to December 2022. Moreover, a search for reports was conducted on Institutional websites to identify documentation published by World Health Organization, United Nations Office on Drugs and Crime, United States Drug Enforcement Administration, and European Monitoring Centre for Drugs and Drug Addiction. Only articles or reports written in English were selected.

RESULTS

Non-fentanyl derived synthetic opioids, i.e., 2-benzylbenzimidazoles (nitazenes), brorphine, U-compounds, AH-7921, MT-45 and related compounds are characterized, describing them in terms of available forms, pharmacology, metabolism as well as their toxic effects. Sample procedures and analytical techniques available for detection and quantification of these compounds in biological matrices are also presented. Finally, as overdoses involving highly potent NSO may be difficult to reverse, the effectiveness of naloxone as a rescue agent in NSO overdose is discussed.

CONCLUSIONS

Current review presents key information on non-fentanyl derived NSO. Access to upto-date data on substances of abuse is of great importance for clinicians, public health authorities and professionals performing analyses of biological samples.

Advances in fentanyl testing

Fentanyl is a synthetic opioid that was approved by the FDA in the late 1960s. In the decades since, non-prescription use of fentanyl, its analogs, and structurally unrelated novel synthetic opioids (NSO) has become a worsening public health crisis. There is a clear need for accessible testing for these substances in biological specimens and in apprehended drugs. Immunoassays for fentanyl in urine are available but their performance is restricted to facilities that hold moderate complexity laboratory licenses. Immunoassays for other matrices such as oral fluid (OF), blood, and meconium have been developed but are not widely available. Point of care tests (POCT), such as lateral flow immunoassays or fentanyl test strips (FTS), are widely available but not approved by the FDA for clinical use. All immunoassays are vulnerable to false positive and false negative results. Immunoassays may or may not be able to detect fentanyl analogs and NSOs. Mass spectrometry (MS) can accurately and reliably measure fentanyl and its major metabolite norfentanyl in urine and oral fluid. MS is available at reference laboratories and large hospitals. Liquid chromatography paired with tandem mass spectrometry (LC-MS/MS) is the most widely used method and has outstanding specificity and sensitivity for fentanyl and norfentanyl. When compared to immunoassays, MS is more expensive, requires more technical skill, and takes longer to result. Newer mass spectrometry methods can measure fentanyl analogs and NSO. Both mass spectrometry assays and immunoassays [in the form of fentanyl test strips (FTS)] have potential use in harm reduction programs.

Determination of 5 synthetic cannabinoids in hair by Segmental analysis using UHPLC-MS/MS and its application to eight polydrug abuse cases

In recent years, an increasing number of new synthetic cannabinoids (SCs) have appeared in the drug trade market. A UPLC-MS/MS method was developed to simultaneously identify five synthetic cannabinoids in 1 cm segment hair samples. The method was fully validated and confirmed to have good selectivity, accuracy, and precision, as well as satisfactory linearity within the calibrated range. The limit of quantification (LOD) was 0.5 pg/mg, and the lower limit of quantitation (LLOQ) was 1 pg/mg, with intraday and interday accuracies (bias) ranging from - 9.6-13.7%. The validated method was successfully used for qualitative and quantitative analysis of five SCs in authentic hair samples of eight SC abusers. SCs were detected in 8 cases at concentrations ranging from 1.5 to 632.9 pg/mg.

Evaluation of Pretreatment and Extraction Parameters for the Analysis of Fentanyl in Hair Using Statistical Design of Experiments (DoE)

Optimal methods for hair analysis are often debated. Previous work in this laboratory demonstrated that the statistical technique known as Design of Experiments (DoE) is useful for such optimization. DoE evaluates both the individual roles and the combinatorial associations among multiple independent variables (i.e., hair pretreatment parameters) and a dependent variable (i.e., drug recovery from hair). In this study, hair externally contaminated with fentanyl underwent decontamination with combinations of parameters based on a 24 fractional factorial block design DoE matrix. The parameters of interest included aqueous wash solvent (1% SDS or water), organic wash solvent (dichloromethane or methanol), number of consecutive washes (one or three), sequence of washes (aqueous first or organic first), and wash time (30 s or 30 min). The optimal method for decontaminating fentanyl from the hair surface was found to be one 30-min wash with dichloromethane followed by one 30-min wash with water. Pretreatment parameters were optimized with a 23 full factorial DoE matrix using authentic hair reference material (HRM), which consisted of pooled drug user hair diluted to a known concentration of fentanyl with drug-free hair. The factors of interest were extraction solvent/sample weight ratio (12.5 or 25 µL/mg), hair particle size (pulverized or 1 mm segments), and extraction time (2 or 24 h). The most effective pretreatment method for fentanyl consisted of pulverizing the hair prior to a 2-h extraction in a 25 µL/mg extraction solvent volume/sample weight ratio. Finally, using the optimized pretreatment methods, fentanyl containing authentic HRM was extracted using aqueous base, solvent, and enzymatic hair extraction methods, where it was determined that the aqueous base technique was most effective for recovery of fentanyl. These experiments further demonstrate the value of DoE and authentic HRM in method development for forensic hair analysis.

Determination of Nine Fentanyl Drugs in Hair Samples by GC-MS/MS and LC-MS/MS

We established GC-MS/MS and LC-MS/MS analysis methods for nine fentanyl drugs in hair samples. Human hairs were prepared by soaking in a solution of water-dimethyl sulfoxide with target analytes. The drugs were norfentanyl, acetyl fentanyl, para-fluorofentanyl, isobutyryl fentanyl, fentanyl, thiofentanyl, 4-fluoroisobutyr fentanyl, ocfentanil, and tetrahydrofuran fentanyl. For a single-factor experiment, a Box-Behnken design-response surface was used to optimize the pretreatment conditions of samples. The prepared samples were quantitatively analyzed by GC-MS/MS and LC-MS/MS. The working curve method was used for quantitative analysis with fentanyl-D5 as the internal standard. The concentrations of the nine fentanyl drugs in the samples were 1.488-6.494 ng mg^-1, RSDs < 5.0%. For GC-MS/MS, the linear range of the nine fentanyl drugs was 0.5-5.0 ng mg^-1, r ² > 0.999. The detection limits were 0.02-0.05 ng mg^-1, and the recovery rates were >86%. For LC-MS/MS, the nine fentanyl drugs had an excellent linear relationship within the concentration range of 3.0-220.0 pg mg^-1, r ² > 0.999. The detection limits were 0.05 pg mg^-1 and the recovery rates were >84%. The established methods were used for the detection of fentanyl drugs in human hairs, with high sensitivity, accuracy, and specificity. These two methods can be used for the certification of fentanyl certified reference substances (CRMs). In the experiment, the developed hair CRMs, which will continue to be studied in the future, are expected to be used in forensic drug abuse detection.

Preparation of bamboo-derived magnetic biochar for solid-phase microextraction of fentanyls from urine

In this study, a biochar-based magnetic solid-phase microextraction method, coupled with liquid chromatography-mass spectrometry (LC/MS), was developed for analyzing fentanyl analogs from urine sample. Magnetic biochar was fabricated through an one-step pyrolysis carbonization and magnetization process, followed by an alkali treatment. In order to achieve desired extraction efficiency, feed stocks (wood and bamboo) and different pyrolysis temperatures (300-700 °C) were optimized. The magnetic bamboo biochar pyrolyzed at 400°C was found to have the greatest potential for extraction of fentanyls, with enrichment factors ranging from 58.9 to 93.7, presumably due to H-bonding and π- π interactions between biochar and fentanyls. Various extraction parameters, such as type and volume of desorption solvent, pH, extraction time were optimized, respectively, to achieve the highest extraction efficiency for the target fentanyls. Under optimized conditions, the developed method was found to have detection limits of 3.1-9.4 ng/L, a linear range of 0.05-10 μg/L, good precisions (1.9-9.4% for intra-batch, 2.9-9.9% for inter-batch), and satisfactory recoveries (82.0-111.3%). The developed method by using magnetic bamboo biochar as adsorbent exhibited to be an efficient and promising pretreatment procedure and could potentially be applied for drug analysis in biological samples. This article is protected by copyright. All rights reserved.

In Vitro and In Vivo Analysis of Fentanyl and Fentalog Metabolites using Hyphenated Chromatographic Techniques: A Review

Fentanyl and fentanyl analogues (also called fentalogs) are used as medical prescriptions to treat pain for a long time. Apart from their pharmaceutical applications, they are misused immensely, causing the opioid crisis. Fentanyl and its analogues are produced in clandestine laboratories and sold over dark Web markets to different parts of the world, leading to a rise in the death rate due to drug overdose. This is because the users are unaware of the lethal effects of the newer forms of fentalogs. Unlike other drugs, these fentalogs cannot be detected easily, as very little data are available, and this is one of the major reasons for the risk of life-threatening poisoning or deaths. Hence, rigorous studies of these drugs and their possible metabolites are required. It is also necessary to develop techniques for the detection of minute traces of metabolites in biological fluids. This Review provides an overview of the application of hyphenated chromatographic techniques used to analyze multiple novel fentalogs, using in vivo and in vitro methods. The article focuses on the metabolites formed in phase I and phase II processes in biological specimens obtained in recent cases of drug abuse and overdose deaths that could be useful for the detection and differentiation of multiple fentalogs.

Quantification of Classic, Prescription and Synthetic Opioids in Hair by LC-MS-MS

The current use and misuse of synthetic and prescription opioids in the USA has reached epidemic status. According to the US Department of Health and Human Services, every day more than 130 people in the USA die after overdosing on opioids, and 2.1 million had an opioid use disorder in 2018. Hair is becoming an alternative matrix of increasing interest in forensic toxicology to investigate drug use and abuse patterns due to its long window of detection. The focus of this project was to develop and validate a method that simultaneously detects and quantifies 27 classic, prescription and synthetic opioids in hair by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Hair samples were decontaminated and pulverized in a bead mill. Twenty-five milligrams of hair powder were incubated in a buffer overnight. Mixed mode cation exchange solid phase extraction was carried out before undergoing reversed-phase chromatographic separation, successfully resolving isobaric opioids. We used two multiple reaction monitoring transitions in positive mode to identify each analyte. The linearity range was 1-500 pg/mg for fentanyl and synthetic opioids and 10-500 pg/mg for prescription and classic opioids. Imprecision was <17.5% and bias ranged from -13.6 to 12.0%. Majority of compounds showed extraction efficiency >50%, and ion suppression from -89.2 to -26.6% (CV < 19%, n = 10). This method was applied to 64 authentic cases, identifying 13 compounds from our panel. A sensitive and specific method was developed for the identification and quantification of 27 classic, prescription and synthetic opioids in hair by LC-MS-MS.

Review of LC techniques for determination of methadone and its metabolite in the biological samples

Methadone (MTD) is a synthetic analgesic drug used for treating opioid dependence and effectively used clinically for patients with severe pain. The abuse of MTD may lead to poisoning, disorder in the central nervous system and even death. The regular monitoring of MTD in biological matrices including serum, plasma and urine samples is an effective way to control abuse of MTD. In this manner, the selection of analytical monitoring of MTD in biological matrices is of paramount importance. This study was conducted to review high-performance liquid chromatography (HPLC) techniques carried out on MTD and its main metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) in the biological samples during 2015-June 2021.

Long-Term Stability of 13 Fentanyl Analogs in Blood

Fentanyl analogs continue to play a major role in proliferating the opioid epidemic in the United States. With high rates of overdose deaths, forensic laboratories experience backlogs, which may lead to false negative results due to drug instability. To address this issue, a quantitative method was validated for fentanyl analogs (3-methylfentanyl, 4-ANPP, 4-fluoro-isobutyrylfentanyl (4-FIBF), acetylfentanyl, acrylfentanyl, butyrylfentanyl, carfentanil, cyclopropylfentanyl, fentanyl, furanylfentanyl, methoxyacetylfentanyl, p-fluorofentanyl, and valerylfentanyl) in blood using liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) and used to assess long-term stability under various temperature conditions (-20°C, 4°C, ~25°C, and 35°C) for 9 months. Authentic specimens were also analyzed 6 months apart for applicability to postmortem blood. Method validation resulted in calibration ranges of 1-100 ng/mL and limits of detection (LOD) of 0.5 ng/mL. Precision and bias were acceptable (within ±7.2%CV and ±15.2%, respectively). Matrix effects exhibited ion enhancement for all analytes, except carfentanil and 4-ANPP in low quality control (>25%). For long-term stability, fentanyl analogs (except acrylfentanyl) remained stable under room temperature and refrigerated conditions at low and high concentrations (81.3-112.5% target) for 9 months. While most fentanyl analogs remained stable frozen, degradation was observed after 2 weeks (4 freeze/thaw cycles). At elevated temperatures, most analytes were stable for 1 week (74.2-112.6% target). Acrylfentanyl was unstable after 24h under elevated (70% loss) and room temperatures (53-60% loss), 48-72h refrigerated (28-40% loss), and 4 weeks frozen (22% loss). In authentic bloods (n=7), initial furanylfentanyl (FuF) and 4-ANPP concentrations were 1.1-3.6 and 1.4-6.4 ng/mL, respectively. Percent loss of FuF and 4-ANPP over 6 months were 16.3-37.4% and 0.2-26.8%, respectively. Samples suspected to contain fentanyl analogs are recommended to be stored refrigerated or frozen with limited freeze/thaw cycles. Due to instability, in the event of an acrylfentanyl overdose, samples should be analyzed immediately or stored frozen with analysis within 1 month.

Isotonitazene: Fatal intoxication in three cases involving this unreported novel psychoactive substance in Switzerland

The paper describes the first three deaths reported in Europe involved in isotonitazene consumption, a potent benzimidazole derivate opioid consumed in the recreational drug scene. Isotonitazene powder and purity determination was performed on the sample collected in the first death scene by NMR, HRMS, GC-FTIR, ATR-FTIR and GC-MS. Isotonitazene purity was determined by GC-MS analysis and proton NMR, and was defined to be above 95 % and 98 %, respectively. Quantification of isotonitazene in biological samples was performed using a targeted analysis based on SPE extraction and ultra-high performance liquid chromatography tandem mass spectrometry. The isotonitazene median concentration in femoral whole blood was 1.20ng/mL. Isotonitazene concentration in hair was similar or even lower compared to that seen in fentanyl abusers. Isotonitazene distribution in tissues converges in the brain, lungs and heart, respectively. Surprisingly, isotonitazene concentration in liver is the lowest measured for all tissues and fluids analyzed. Based on circumstantial evidence, autopsy findings and the results of the toxicological analysis, the medical examiner concluded that the cause of all three deaths was an acute intoxication with isotonitazene. Since isotonitazene toxic concentration levels are very low, the consumption of this new psychoactive drug is a real hazard for human health.

Recent bionalytical methods for the determination of new psychoactive substances in biological specimens

One of the problems associated with the consumption of new psychoactive substances is that in most scenarios of acute toxicity the possibility of quick clinical action may be impaired because many screening methods are not responsive to them, and laboratories are not able to keep pace with the appearance of new substances. For these reasons, developing and validating new analytical methods is mandatory in order to efficiently face those problems, allowing laboratories to be one step ahead. The goal of this work is to perform a critical review regarding bionalytical methods that can be used for the determination of new psychoactive substances (phenylethylamines, cathinones, synthetic cannabinoids, opioids, benzodiazepines, etc), particularly concerning sample preparation techniques and associated analytical methods.

Identification of furosemide in hair in a post-mortem case by UHPLC-MS/MS with guidance on interpretation

Testing for drugs in hair raises several difficulties. Among them is the interpretation of the final concentration(s). In a post-mortem case, analyses revealed the presence of furosemide (12 ng/mL) in femoral blood, although it was not part of the victim's treatment. The prosecutor requested our laboratory to undertake an additional analysis in hair to obtain information about the use of furosemide. A specific method was therefore developed and validated to identify and quantify furosemide in hair by UHPLC-MS/MS. After decontamination of 30 mg of hair, incubation in acidic condition, extraction with ethyl acetate, the samples were analyzed by UHPLC-MS/MS. Furosemide was found in the victim's hair at 225 pg/mg. However, it was not possible to interpret this concentration due to the absence of data in the literature. Therefore, the authors performed a controlled study in two parts. In order to establish the basis of interpretation, several volunteers were tested (four after a single 20 mg administration and twenty-four under daily treatment). The first part indicated that a single dose is not detectable in hair using our method. The second part demonstrated concentrations ranging from 5 to 1110 pg/mg with no correlation between dosage and hair concentrations. The decedent's hair result was interpreted as repeated exposures. In the case of furosemide analysis, hair can provide information about its presence but cannot give information about dosage or frequency of use.

Determination of fentanyl and 19 derivatives in hair: Application to an Italian population

Nowadays fentanyl and its analogs represent the most numerous group among synthetic opioid and, due to their higher potency in comparison to traditionl opioids, the main cause of the critical increase of fatal intoxications opioids-intake related in the USA. We developed an LC-MS/MS method for the detection and quantification of fentanyl and its analogs in hair, then applied to 117 real samples, 97 collected from drugs users and 20 from postmortem cases of drugs addicts. The ionization and MRM parameters have been optimized for 27 molecules: 20 reached the acceptance criteria for identification and quantification. LODs and LOQs of 0.2 and 0.5 pg/mg, respectively, were reached for most of the substances, except for five compounds for which were set at 0.5 and 1.0 pg/mg. 2 out of the 97 samples collected from drug users tested positive; one for carfentanil, butyryl fentanyl, THFF and ocfentanil; the other one for 3-methyl norfentanyl. 2 out of the 20 postmortem samples show positive results: one only for fentanyl, the other for furanyl fentanyl, acetyl fentanyl, methoxyacetyl fentanyl, methoxyacetyl norfentanyl, ocfentanil and 4-ANPP. Despite the relatively small number of samples, the results suggest that the method should be included in routine hair analyses for monitoring the new synthetic opioids potential intake by drug users.

Development and validation of liquid chromatography-tandem mass spectrometry targeted screening of 16 fentanyl analogs and U-47700 in hair: Application to 137 authentic samples

This study was to validate a LC-MS/MS method for the determination of 17 new synthetic opioids (NSOs) in hair including 3-fluorofentanyl, 3-methylfentanyl, acetylfentanyl, acetylnorfentanyl, alfentanyl, butyrylfentanyl, butyrylnorfentanyl, carfentanil, fentanyl, furanylfentanyl, furanylnorfentanyl, methoxyacetylfentanyl, norcarfentanil, norfentanyl, ocfentanil, sufentanil, and U-47700, and to apply it to 137 authentic samples. Twenty milligrams of hair was decontaminated in dichloromethane and underwent liquid extraction. 10 μL of the reconstituted residue were injected onto the system. The separation was performed in 12 minutes in a gradient mode at a flow rate of 300 μL/min using a Hypersyl Gold PFP column (100 × 2.1 mm i.d., 1.9 μm) maintained at 30°C. Compounds were detected in positive ionization and MRM modes using a TSQ Endura mass spectrometer (ThermoFisher). The method was validated according to EMA guidelines. The LLOQ was in the range 1-50 pg/mg, and the calibration ranged from the LLOQ-1000 pg/mg. Intra- and inter-day accuracy (bias) and precision were < 15%. Extraction recoveries of parent drugs and metabolites were 74-120% and 7-62%, respectively. The matrix effect was in the range 59-126% (CVs ≤ 12.9%). Fentanyl was found in six cases at concentrations of < 1-1650 pg/mg (n = 14 segments). Five fentanyl analogs were quantified in two cases: 3-fluorofentanyl (25-150 pg/mg, n = 5), furanylfentanyl (15-500 pg/mg, n = 5), methoxyacetylfentanyl (500-600 pg/mg, n = 2), acetylfentanyl (1 pg/mg, n = 2), carfentanyl (2.5-3 pg/mg, n = 2). This fully validated method allowed us to test for the first time 3-fluorofentanyl and norcarfentanil in hair among 15 other NSOs, and brings new data regarding 3-fluorofentanyl and methoxyacetylfentanyl hair concentrations.