Qualitative analysis of seized cocaine samples using desorption electrospray ionization‐ mass spectrometry (DESI‐MS)

Desorption electrospray ionization ‐ mass spectrometry (DESI‐MS) is a useful technique for the qualitative analysis of compounds found in seized drug material. In this study, DESI‐MS was utilized in the screening analysis of illicit cocaine samples. The technique was also applied to the geographical origin determination of these samples. The limit of detection was determined to be 24.3 µg (or 3.47 µg/mm²) and the analysis time was less than 1 minute per sample. The intra‐day and inter‐day precision for the detection of cocaine was 11 % and 42 %, respectively; therefore the quantitative data provided by DESI‐MS was limited in its use for accurate determination of cocaine concentration in a sample. Using the quadrupole time‐of‐flight (QTOF) mass spectrometer, the presence of cocaine and impurities detected were confirmed by accurate tandem MS data. The qualitative chemical profiles obtained using DESI‐MS were compared to two popular analysis techniques, GC‐MS and LC‐MS. The effects of a range of adulterants including caffeine, procaine, levamisole, lignocaine, paracetamol, and atropine on the detectability of cocaine were also investigated. It was found that the addition of these adulterants in a cocaine sample did not prevent the detection of the analyte itself (there was slight enhancement in some samples), which was useful in drug detection. The detection of truxillines in the seized samples by DESI‐MS aided in the preliminary determination of geographical origin, i.e., Bolivian, Peruvian or Colombian leaf origin. The application of DESI‐MS to the qualitative analysis and screening of seized cocaine samples demonstrates the potential and applicability of the technique to the fast chemical profiling of illicit samples. Copyright © 2014 John Wiley & Sons, Ltd.     

Levamisole-Adulterated Cocaine: What about in European Countries?

Background: A wide variety of somatic complications is reported or expected among cocaine users because of the adulterant levamisole. Most of the reports come from North America. Methods: To update the data on levamisole-adulterated cocaine in European countries, we present here a synthesis of data on samples seized by the police with the detection of levamisole, the amount of levamisole in cocaine samples, European drug information reports, and clinical cases. Results: Although there is a variation in the percentage of levamisole in cocaine samples between European countries, the trend is an increase of these percentages. As in North America, levamisole is becoming the most common cocaine adulterant. First European cases of complications secondary to the use of adulterated cocaine with levamisole were skin necrosis, vasculitis, and agranulocytosis. Levamisole postmortem data concerned two cases of complications leading to death, possibly related to levamisole or its metabolite (acute coronary syndrome, pulmonary hypertension). Conclusion: Even if it is difficult to have a global European view with comparable data, levamisole is present in European cocaine specimens and can lead to severe adverse health effects. However data on the prevalence of toxicity related to levamisole-adulterated cocaine abuse are missing.     

Composition,purity and perceived quality of street cocaine in France

BackgroundThere is little knowledge about the composition and cocaine content of street cocaine, nor about what users know about it.Method373 cocaine users were face to face interviewed between May and December 2006 about the last sample of cocaine they had consumed and residual amounts of the substances actually used were analysed using gas phase chromatography coupled to mass spectrometry (GC–MS). Users rated the perceived quality of their product (“good”, “average”, “poor”), its “estimated percentage of cocaine” and any cutting agents it contained. Price, quantity, place of purchase (street, dealer's premise, appointment), mode of administration (sniffing, injection, smoking) and the supposed nature of the sample (natural, synthetic, no distinction ever made) were also reported. Perceived quality was modelled using multivariate multinomial regression.ResultsThe median cocaine content was 22%. Altogether, 343 samples contained cocaine, among which 75% contained at least one adulterant. The most frequently occurring were phenacetin (54% of the samples), caffeine (17%), paracetamol (14%), diltiazem and lidocaïne (11%). Users showed relatively poor discrimination concerning cocaine purity, and only 12% reported at least one of the detected adulterants. The major determinants of their perception of cocaine quality were: place of purchase, natural origin, price per gram, actual cocaine content and mode of administration.ConclusionThe composition of street cocaine is largely unknown to users. Users’ perceptions of cocaine quality are based partly on false beliefs and certain administration modes. This may contribute to favouring very risky practices. The effects of adulterants on users’ health should be investigated.     

Practical tool for sampling and fast analysis of large cocaine seizures

Large quantities of illicit drugs are frequently seized by law enforcement. In such cases, a representative number of samples needs to be quickly examined prior to destruction. No procedure has yet been set up which rapidly provides information regarding the homogeneity of the samples, the presence of controlled substances, and the degree of purity. This study establishes a protocol for fast analysis of cocaine and its most common cutting agent, levamisole, in large seizures. The protocol is based on a hypergeometric sampling approach combined with Fourier‐transform infrared (FTIR) spectrometry and support vector machines (SVM) algorithms as analysis methods. To demonstrate the practical use of this approach, 5 large cocaine seizures (consisting between 45 and 85 units) were analysed simultaneously with gas chromatography–mass spectrometry (GC–MS), gas chromatography–flame ionisation detector (GC–FID), and a portable FTIR spectrometer using attenuated total reflectance (ATR) sampling combined with SVM models. According to the hypergeometric sampling plan of the guidelines of the Drugs Working Group (DWG) of the European Network of Forensic Science Institutes (ENFSI), the required number of subsamples ranged between 19 and 23. Considering the identification analyses, the SVM models detected cocaine and levamisole in all subsamples of Cases 1 to 5 (100% correct classification), which was confirmed by GC–MS analysis. Considering the quantification analyses, the SVM models were able to estimate the cocaine and levamisole content in each subsample, compared to GC–FID data. The developed strategy is easy, cost effective, and provides immediate information about both the presence and concentration of cocaine and levamisole. By using this new strategy, the number of confirmation analyses with laborious and expensive chromatographic techniques could be significantly reduced.     

Adulterants in heroin/cocaine: Implications concerning heroin-associated nephropathy

Heroin-associated nephropathy (HAN) is a complication of the intravenous use of heroin or cocaine. It has been postulated that one of the substances used to adulterate these drugs may be responsible for the renal injury. We examined data provided by the Drug Enforcement Administration (DEA) concerning the laboratory analysis of 12 366 samples of heroin/ cocaine. These street-grade drugs were analyzed for the presence of various adulterants or secondary substances. Eleven adulterants were identified with a frequency of occurrence that exceeded 5%. Quinine, mannitol, lactose and procaine were the non-narcotic compounds most commonly found. Other substances found included caffeine, inositol, lidocaine, starches, methapyrilene, sucrose, acetylprocaine and dextrose. No specific substance including heroin or cocaine has yet been definitely implicated as causative of HAN. These data suggest that further animal research is needed to determine the effects of repeated intravenous injections of each of these commonly found substances on the kidney.     

Analytical findings in used syringes from a syringe exchange program

BackgroundSince it's first implementatation in 1984, Syringe Exchange Programs (SEP) are a critical component of harm reduction interventions among people who inject drugs.. The aim of this work was to use a scientific analytical approach to obtain drug use information through the analysis of the content of used syringes.Methods357 syringes were collected in New York City and submitted to qualitative analysis. Screening analysis was performed by gas chromatography mass spectrometry (GC–MS) and confirmatory analysis by liquid chromatography quadrupole time of flight mass spectrometry (LC-QTOF).ResultsOf the 357 syringes analyzed, 275 (77.0%) were positive for one or more substances. The most common drug of abuse identified was heroin/related substances (72.0%), followed by cocaine/related substance (34.9%), fentanyl/related substance (13.5%), methamphetamine/related substance (7.6%) and furanylfentanyl (3.6%). Quinine/quinidine (18.5%) was the most common cutting agent detected, followed by levamisole (12.0%), caffeine (11.6%), lidocaine (11.6%), and phenacetin (6.9%).ConclusionAnalysis of samples collected from a drug street scenario allows the identification of new substances being injected and provides information to harm reduction programs to identify strategies to reduce drug abuse.     

Temporal and geographic variations in the characteristics of heroin seized in Spain and their relation with the route of administration

We studied the evolution of the purity and other characteristics of heroin seized in 17 Spanish provinces (especially seizures presumed to be street drugs) and explored their relation with the prevalence and recent changes in intravenous use. We found great variability in purity within and between provinces: in provinces with large cities the purity is similar to or greater than that detected elsewhere in Europe, in others it is less than 30%, and on the island of Mallorca it is over 60%. Purity has increased in recent years. The heroin in circulation is predominantly brown in all of Spain except on the Mediterranean coast. The principal adulterants detected are caffeine, paracetamol and piracetam; phenobarbital and procaine have disappeared. In provinces where white heroin is in circulation, most heroin users in treatment use the intravenous route; in provinces where brown heroin predominates, the proportion of chasers increases with increasing purity of heroin (correlation coefficient = 0.6). The disappearance of white heroin has paralleled the spread of the phenomenon of chasing.     

An evaluation of the results of a drug sample analysis

An analysis of drug samples received by the National Toxicology Institute at Madrid during the period from September 1985 to May 1987 was undertaken with a view to carrying out an epidemiological assessment of drug abuse. Of 414 street drug samples, 63.5 per cent contained heroin, 12.5 per cent cocaine, 8.5 per cent amphetamine and 15.4 per cent other substances. The concentration of heroin ranged from 21 to 60 per cent in most of the samples (91.8 per cent) that contained it. Similar concentrations of cocaine were found in the samples containing that substance. Adulterants were detected in 78.8 per cent of the samples containing heroin, 59.6 per cent of the samples containing cocaine and 56 per cent of the samples containing amphetamine. The most common adulterants in the samples containing heroin were caffeine (68.4 per cent), phenobarbital (19.7 per cent), methaqualone (13.4 per cent) and procaine (13.4 per cent), while lidocaine was the most common adulterant (52 per cent) in the samples containing cocaine.     

Determination of aminorex in human urine samples by GC-MS after use of levamisole

The Drug Enforcement Administration (DEA) reports that as of October 2010, 79% of all cocaine seized in the United States contained levamisole. The equine conversion of levamisole to aminorex has been demonstrated. However, the metabolic fate of levamisole in humans is unknown. Nevertheless, as aminorex is amphetamine-like and hallucinogenic, it may be used as an adulterant to increase the effects of cocaine. We report here the results of in vivo studies demonstrating for the first time that not only equine, but also canine and human metabolism all result in aminorex formation. Levamisole and aminorex were extracted from real urine samples by liquid-liquid extraction and identified and quantified by GC-MS (identification by 3 ions per substance, LLOQ at 0.15ng/ml for both).     

Cocaine adulteration with the anthelminthic tetramisole (levamisole/dexamisole): Long‐term monitoring of its intake by chiral LC–MS/MS analysis of cocaine‐positive hair samples

Recent studies indicate that not only the anthelminthic levamisole but also the racemate tetramisole (R‐/S‐phenyltetraimidazothiazole, PTHIT) was found as an adulterant for cocaine. We herein report on the investigation of the prevalence of PTHIT among cocaine‐positive hair samples and the discrimination of the presence of its stereoisomers levamisole and dexamisole. Cocaine‐positive hair samples were collected in a forensic context in 2015 and mainly 2017 (n = 724). Cocaine and PTHIT concentrations have been determined by achiral liquid chromatography–tandem mass spectrometry (LC–MS/MS). For distinction of levamisole/dexamisole chiral LC–MS/MS was performed. Cocaine hair concentrations ranged from 500 (cut‐off) to approximately 800 000 pg/mg. The study demonstrates a strong prevalence of PTHIT in cocaine users' hair (87%, n = 627). PTHIT hair concentrations ranged from below LLOQ 3.5 to approximately 61 000 pg/mg (median: 260 pg/mg). Surprisingly, enantiomeric ratios of levamisole/dexamisole ranged from 0.17 to 1.34 (median: 0.63). Therefore, PTHIT‐adulterated street cocaine samples (n = 24) seized between 2013 and 2016 were tested. Samples mainly contained racemic tetramisole (87.5%), only one sample contained levamisole only and two samples contained non‐racemic PTHIT. Our experiments suggest that the presence of tetramisole in biological samples may have hitherto been underestimated. Most probably higher dexamisole than levamisole concentrations in hair specimens arise from stereoselective metabolism and/or elimination. This is particularly important in light of the different pharmacological activities of the two enantiomers and potentially different adverse effects. Toxicological interpretations in intoxication cases with adulterated cocaine should not only consider levamisole but also tetramisole and terminology in scientific contributions should be used accordingly.     

Susac-Like Syndrome in a Chronic Cocaine Abuser: Could Levamisole Play a Role?

Introduction

Toxic leukoencephalopathy is a possible but rare complication of chronic cocaine abuse. The role of adulterants, mainly levamisole, is still debated.

Case Report

We describe an atypical case of fatal leukoencephalopathy mimicking Susac syndrome in a 22-year-old man who was chronically abusing cannabis and cocaine. Exposure to levamisole as adulterant to cocaine was proven by hair analysis. Despite cessation of exposure to cocaine and aggressive immunosuppressive therapy, the patient remained in a minimally conscious state until death.

Discussion

Susac syndrome is a rare entity, and its etiology is not yet fully elucidated. The toxic etiologies have been poorly investigated to date. Further observations are required to determine if cocaine and/or adulterants might play a significant role.     

Palpable purpura complicated by streptococcal toxic shock syndrome resulting in limb necrosis and amputation: a case of levamisole and cocaine coingestion

Palpable purpura resulting from cocaine and levamisole coingestion has been reported with increasing frequency over the last several years as distribution of this drug combination becomes more universal. Toxicity from ingestion of this dangerous combination is difficult to diagnose due to the multitude of possible clinical presentations, variety of possible adulterants, and elusive nature of levamisole given its short half-life and limited availability of detection methods. Levamisole is a chemotherapeutic and immunomodulatory agent currently marketed as a veterinary anthelmintic. We describe the case of a 48-year-old woman admitted to our intensive care unit with a diagnosis of streptococcal toxic shock syndrome (STSS), confirmed from fluid taken from an elbow lesion that grew Streptococcus pyogenes. She was noted to have bullae of the elbow and diffuse purpura with necrotic centers covering a large portion of her body (trunk, legs, arms, back, toes, fingers, and tip of nose). On further evaluation, she was found to have ingested levamisole-tainted cocaine. The patient's complications related to either cocaine and levamisole coingestion or STSS included thrombocytopenia, acute renal failure, and limb necrosis. Thrombocytopenia gradually improved upon treatment with prednisone, and acute renal failure improved with intravenous fluid resuscitation; however, she subsequently required several appendage amputations due to severe gangrene. Clinicians must have high suspicion for ingestion of this drug combination and request prompt testing of urine samples for levamisole if a patient who admits to illicit drug use presents with purpuric or necrotic skin lesions.     

Chiral pharmacokinetics of tetramisole stereoisomers—Enantioselective quantification of levamisole and dexamisole in serum samples from users of adulterated cocaine

Phenyltetrahydroimidazothiazole (PTHIT, tetramisole) is the most frequently used adulterant of cocaine and exists in the two enantiomeric forms levamsiole (S) and dexamisole (R). Existing studies show diverse fractions of samples containing enantiopure levamsiole, levamisole-enriched mixtures, and racemic tetramisole as adulterant. However, blood samples have never been enantioselectively tested for PTHIT. Because enantiomers are usually metabolized stereoselectively, chiral analysis of blood samples can help estimate the time of drug use, provided that a racemic substance is ingested. Therefore, an enantioselective liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed using a chiral column. Validation of the method was carried out for methanolic substance samples as well as serum samples and showed satisfactory selectivity, sensitivity, linearity (0.05–100 ng/mL), precision, and accuracy; 151 cocaine samples seized in Germany between 2018 and 2021 were analyzed. Most (94%, n = 48) of the 51 PTHIT-positive samples contained racemic tetramsiole, whereas there were two samples containing levamisole-enriched mixtures and one sample containing nearly enantiopure levamisole. Furthermore, 157 cocaine and/or benzoylecgonine-positive forensic serum samples were tested with cocaine-positive samples showing the highest frequency of PTHIT detection (43%). All positive samples contained either dexamisole alone or (R)/(S)-concentration ratios >1 (1.05–70.6). Finally, a self-administration study was conducted with three subjects taking 10 mg of racemic tetramisole each. Although peak concentrations and corresponding times did not differ significantly between the enantiomers, dexamisole showed significantly longer apparent elimination half-lives (7.02–10.0 h) than levamisole (2.87–4.77 h). The resulting steadily increasing (R)/(S)-ratios can therefore be helpful in estimating the time of cocaine consumption.     

Determination of phenyltetrahydroimidazothiazole enantiomers (Levamisole/Dexamisole) in illicit cocaine seizures and in the urine of cocaine abusers via chiral capillary gas chromatography-flame-ionization detection: clinical and forensic perspectives

Illicit cocaine laboratories in South America have been adding phenyltetrahydroimidazothiazole enantiomers (levamisole and/or tetramisole) to refined illicit cocaine for over 8 years. A chiral capillary gas chromatographic methodology is presented for phenyltetrahydroimidazothiazole enantiomer determination in illicit cocaine samples and in the urine of cocaine abusers. Illicit cocaine samples (N = 752) and urine specimens from cocaine abusers (N = 50) that contained phenyltetrahydroimidazothiazole were analyzed for enantiomeric composition. Legitimate commercial preparations of phenyltetrahydroimidazothiazole are either 100% levamisole or a 50:50 mixture of levamisole and dexamisole (tetramisole). Specimens that contain phenyltetrahydroimidazothiazole mixtures that are other than 50:50 preparations will be enhanced in one isomer over the other, and they are referred to as either "levamisole-enhanced" or "dexamisole-enhanced". Cocaine samples were found to contain levamisole (N = 495, 66%), tetramisole (N = 143, 19%), and levamisole-enhanced enrichment (N = 114, 15%); urine specimens contained levamisole (N = 23, 46%), levamisole-enhanced enrichment (N = 10, 20%), and dexamisole-enhanced enrichment (N = 13, 26%). The toxicological and forensic aspects of these findings are discussed.     

2005年北京地区海洛因毒品中稀释剂的分析

目的:对2005年收缴的"零包"海洛因毒品中的稀释剂进行分析。方法:准确称取可疑毒品适量,用SKF525做内标,用乙醇配制成1.0mg.kg-1的样品溶液,取1μl进行GC/MS分析。结果:在408份"零包"海洛因毒品中,检测出含有机稀释剂的323份,占79.2%。检测出的有机稀释剂是烟酰胺(231份,占总份数的56.6%)、咖啡因(135份,占总份数的33.1%)、扑热息痛(51份,占总份数的12.5%)、氨基比林(39份,占总份数的9.6%)、茶碱(37份,占总份数的9.1%)、非那西丁(29份,占总份数的7.1%)、脑复康(28份,占总份数的6.9%)、镇静催眠药(10份,占总份数的2.4%)、曲马朵及其它(10份,占总份数的2.4%)。结论:北京地区"零包"海洛因毒品中多数有有机稀释剂,且种类繁多。脑复康是一个新发现的稀释剂。     

Heroin purity and composition in Sydney, Australia

The aim of the study was to provide baseline data on the pharmacological properties of heroin available for retail sale in Cabramatta, Sydney. A retrospective sampling frame was constructed consisting of all suspected heroin seizures in Cabramatta between October 1996 and March 1997 ( n = 487). A total of 33 street-level 'exhibits', comprising 88 samples, were selected. Ion chromatography was used to determine whether heroin was present as the free base or as the hydrochloride (or other salt). High performance liquid chromatography with diode array detection was used to assess the presence of diacetylmorphine hydrochloride (heroin hydrochloride), O-6-monoacetylmorphine hydrochloride (degradation product) and acetylcodeine hydrochloride (synthesis byproduct). Gas chromatography/mass spectrometry and high performance liquid chromotography with refractive index detection were used to detect adulterants and diluents. All samples contained heroin as the hydrochloride salt. No heroin free base was encountered. The mean purity was 66% with 85% of samples having an average purity of at least 50%. The samples were free of harmful adulterants. Adulterants detected were pharmacologically inactive diluents largely used to add bulk (sugars) or pharmacologically active adulterants used to improve the bioavailability of heroin HCL when smoked (caffeine). Results have implications for attempts to reduce drug-related harms and, in particular, suggest that interventions designed to facilitate transitions from heroin injecting to smoking require careful consideration of the pharmacological factors associated with route of administration.     

Methaemoglobinaemia associated with the use of cocaine and volatile nitrites as recreational drugs: a review

Methaemoglobinaemia can cause significant tissue hypoxia, leading to severe, potentially life-threatening clinical features and/or death. Over recent years there have been increasing reports of methaemoglobinaemia related to recreational drug use. There have been 25 articles describing methaemoglobinaemia related to recreational use of volatile nitrites (poppers) and more recently, four reports of methaemoglobinaemia in association with recreational cocaine use. In this article we discuss the mechanisms by which methaemoglobinaemia occurs in relation to the use of both volatile nitrites and cocaine, and summarize the published cases of recreational drug-related methaemoglobinaemia. The volatile nitrites can cause methaemoglobinaemia directly through their activity as oxidizing agents. However, with cocaine, methaemoglobinaemia is related to adulterants such as local anaesthetics or phenacetin, rather than to the cocaine itself. Clinicians managing patients with acute recreational drug toxicity should be aware of the potential for methaemoglobinaemia in these patients, particularly in patients with cyanosis or unexplained low oxygen saturations on pulse oximetry, and ensure that appropriate and timely management is provided, including, where appropriate, the use of methylthioninium chloride (methylene blue).     

New qualitative analysis strategy for illicit drugs using Raman spectroscopy and characteristic peaks method

Performing fast qualitative identification of seized illegal drugs by Raman spectroscopy is challenging due to fluorescence interference as well as chemical complexity. Spectrometers with 785-nm excitation, 1,064-nm excitation, and sequentially shifted excitation (SSE) were compared for their effect on fluorescence reduction. The characteristic peaks method, which is independent of cutting agents, was tested as a new strategy to broaden the application of the Raman technique. The suitability of the characteristic peaks method was fully examined by analyzing a large amount of seized illegal drugs, including 72 methamphetamine hydrochloride (concentration range of 13.9%–99.4%), 68 ketamine hydrochloride (17.7%–99.8%), 176 heroin hydrochloride (5.2%–79.5%), 51 cocaine hydrochloride (21.1%–94.5%), and 33 cocaine base (30.9%–92.5%) samples. The results showed that seized methamphetamine, ketamine, and cocaine samples had no or little fluorescence. Hence, in regard to detection of these samples, the advantage of using 1,064-nm excitation and SSE compared with 785-nm excitation was quite limited. Regarding the heroin samples, a significant improvement of the “high” confident positive detected rate was evident for 1,064 nm excitation (60.8%) and SSE (61.4%), compared with 785-nm excitation (13.1%). However, it was also seen that even if 1,064-nm excitation and SSE were applied, the fluorescence of heroin samples was still unable to be fully overcome. By using the characteristic peaks method, low LOD results of 5%–20% were acquired for 40 types of drug mixtures, and lower LODs were obtained for the 60% of the drug mixtures compared with library searching method. Raman spectroscopy in conjunction with the characteristic peaks method was shown to be fast, simple, accurate, and sensitive in the qualitative analysis of seized drug samples.     

Detection of levamisole exposure in cocaine users by liquid chromatography-tandem mass spectrometry

Levamisole, a veterinary antihelminthic, was recently recognized as an adulterant in cocaine and is known to cause severe adverse reactions in some cocaine users. Because of the health concerns involving levamisole-adulterated cocaine, we developed a liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the detection of levamisole in urine. This method was used to determine the prevalence of levamisole in cocaine-positive patient samples. All cocaine-positive urine samples that were sent to the San Francisco General Hospital Clinical Laboratory were tested for levamisole for one month. For LC, an Agilent 1200 series was used with a C(18) column and a gradient of mobile phase A (0.05% formic acid) and B (acetonitrile/methanol). Detection was carried out with an Applied Biosystems QTRAP(?) LC-MS-MS. The levamisole LC-MS-MS method was linear over the range of 5-2500 ng/mL (r > 0.996). Interassay and intraassay CVs were < 6%. The lower limit of detection for levamisole was 0.5 ng/mL. Out of 949 total urine drug screens, 20% were positive for benzoylecgonine, and of those, 88% were positive for levamisole. The high prevalence of levamisole-adulterated cocaine and potential toxicity in cocaine users is a serious public health concern. These findings validate the utility of an LC-MS-MS method for the detection of levamisole.     

Prevalence and co‐existence of active components of ‘legal highs’

The results of a study performed on samples of ‘legal highs’ seized in head shops by law enforcement and health services in Poland between mid‐2008 and mid‐2011 are presented. In total, 449 preparations which differed in labelling, net masses, forms of distribution, etc., were analyzed. A variety of sophisticated analytical methods, including gas chromatography–mass spectrometry (GC‐MS), liquid chromatography‐quadropole time‐of‐flight mass spectrometry (LC‐QTOF‐MS), high performance liquid chromatography (HPLC), and nuclear magnetic resonance (NMR) were applied for component identification and quantification. The most common ingredients of legal highs were (in descending order): MPDV, caffeine, butylone, TFMPP, lidocaine, 4‐MEC, mephedrone, pFPP, BZP, and MDPBP. The scatter of substances changed over time, and piperazines were often ousted by cathinones. Most of the preparations were composed of two or more ingredients. Cathinones and piperazines were mixed mainly within the chemical classes (77.6% and 56.1% of dual links, respectively), caffeine was mixed both with piperazines (24 products) and cathinones (22 products), whereas lidocaine only with the latter class (47 products). A great inconsistency in the qualitative and quantitative composition of products with identical labelling was shown in an example of Coco products seized after August 2010; we found 10 different single component or mixture preparations, and the content of individual ingredients varied from several to hundreds of mgs. This paper summarizes potential dangers connected with the uncontrolled sale of psychoactive substances, and indicates important issues concerning the analysis of legal highs. Copyright © 2012 John Wiley & Sons, Ltd.