A study of the thermal decomposition of adulterated cocaine samples under optimized aerobic pyrolytic conditions.

The pyrolysis behaviour of pure cocaine base as well as the influence of various additives was studied using conditions that are relevant to the smoking of illicit cocaine by humans. For this purpose an aerobic pyrolysis device was developed and the experimental conditions were optimized. In the first part of our study the optimization of some basic experimental parameters of the pyrolysis was performed, i.e., the furnace temperature, the sampling start time, the heating period, the sampling time, and the air-flow rate through the system. The second part of the investigation focused on the volatile products formed during the pyrolysis of a pure cocaine free base and mixtures of cocaine base and adulterants. The anaesthetics lidocaine, benzocaine, procaine, the analgesics phenacetine and paracetamol, and the stimulant caffeine were used as the adulterants. Under the applied experimental conditions complete volatilization of the samples was achieved, i.e., the residuals of the studied compounds were not detected in the pyrolysis cell. Volatilization of the pure cocaine base showed that the cocaine recovery available for inhalation (adsorbed on traps) was approximately 76%. GC-MS and NMR analyses of the smoke condensate revealed the presence of some additional cocaine pyrolytic products, such as anhydroecgonine methyl ester (AEME), benzoic acid (BA) and carbomethoxycycloheptatrienes (CMCHTs). Experiments with different cocaine-adulterant mixtures showed that the addition of the adulterants changed the thermal behaviour of the cocaine. The most significant of these was the effect of paracetamol. The total recovery of the cocaine (adsorbed on traps and in a glass tube) from the 1:1 cocaine-paracetamol mixture was found to be only 3.0+/-0.8%, versus 81.4+/-2.9% for the pure cocaine base. The other adulterants showed less-extensive effects on the recovery of cocaine, but the pyrolysis of the cocaine-procaine mixture led to the formation of some unique pyrolytic products. Two of them were identified as para-aminobenzoic acid (p-ABA) and 2-(diethylamino)ethylbenzoate (DEAEB).

Evidence on unusual way of cocaine smuggling: cocaine-polymethyl methacrylate (PMMA) solid solution--study of clandestine laboratory samples.

An abandoned clandestine laboratory was seized in Slovenia. All confiscated exhibits were analysed in a forensic laboratory, where the following analytical methods were applied: capillary gas chromatography coupled with mass spectrometry (GC-MS) combined also by solid-phase micro extraction (SPME) and pyrolysis (Py) technique, Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy with energy dispersive X-ray detector (SEM-EDX). The most interesting analytical findings can be summarised as follows: at the crime scene some plastic pieces, which contained cocaine dissolved (as solid solution) in polymethyl methacrylate-plexiglass (PMMA), were found. The highest cocaine concentration measured in the plastic sample was about 15% by weight. Two larger lumps of material (12 and 3 kg) were composed mainly of PMMA and CaCO3 and contained only 0.4 and 0.5% of cocaine, respectively. As for the low cocaine concentration, we assume that those two lumps of material represent discarded waste product--residue after the isolation of cocaine from plastic. Higher quantities of pure solvents (41 l) and solvent mixtures (87 l) were seized. We identified three types of pure solvents (acetone, gasoline and benzine) and two different types of solvent mixtures (benzine/acetone and gasoline/acetone). The total seized volume (87 l) of solvent mixtures holds approximately 395 g of solid residue formed mainly of PMMA and cocaine. Obviously solvent mixtures were used for isolation of cocaine from the plastic. Small quantities of relatively pure cocaine base were identified on different objects. There were two cotton sheets, most probably used for filtration. One sheet had traces of cocaine base (76% purity) on the surface, while cocaine in hydrochloride form (96%) was identified on the other sheet. GC-MS analyses of micro traces isolated from analytical balances showed the presence of cocaine and some common adulterants: phenacetine, lidocaine and procaine. A cocaine sample compressed in the shape of block was also seized. The above analytical findings inferred us to the conclusion that the illicit laboratory was used for the isolation of cocaine from PMMA resin. Further more, analyses confirm that not only isolation but also further manipulation of cocaine, i.e. adulteration/dilution, as well as the formation of cocaine blocks took place in the house. The information obtained through analyses also allowed us to make some hypotheses about possible multistage isolation procedure.

4-Dimethylaminopyridine as a catalyst in heroin synthesis.

In this paper, we describe an acetylating method for fast synthesis of heroin from morphine in the presence of 4-dimethylaminopyridine (4-DMAP) as a catalyst. In the reaction which led to heroin formation, the morphine base was subjected to a solution made up of 4-DMAP (catalyst), methylene chloride (solvent) and acetic anhydride (acetylating agent). We showed that in comparison with classic acetylating procedures, reaction time can be reduced from at least several hours at elevated temperatures to <10 min at room temperature. In general, reaction time is dependent on the molar concentration ratio between morphine and 4-DMAP.

In common batch searching of illicit heroin samples--evaluation of data by chemometrics methods.

In this study three illicit heroin samples which belonged to three different batches were subdivided into eight samples each. To simulate the dealers' chain, and to check the influence (if any) of diluents on the analytical results, some of the samples were cut with the most frequently used cutting substances, whereas the others were left unchanged. Samples were analysed (within a 10-week period of time) by gas chromatography-mass spectrometry (GC-MS) and characterised by seven variables each. To recover batch links among investigated heroin samples three multivariate methods, i.e. hierarchical clustering (HCA), principal component analysis (PCA) and k-nearest neighbours (k-NN), were applied on to the normalised and scaled analytical dataset. The classification abilities of the HCA, PCA and k-NN were in the range from 95 to 100%. Disturbing effects due to the dilution of samples have not been observed.

Noscapine as an adulterant in illicit heroin samples.

In this short report the evidence is given (based on the analyses of 22 case samples) that noscapine can be used as an adulterant in illicit heroin samples. In this context, the appearance of illicit heroin samples characterised by a high noscapine content (up to 61%) and a high noscapine/whole morphine ratio (up to 3.5) is highlighted. All samples discussed in the paper (132) were seized in Slovenia, in the period from 1997 to 1999 and were analysed by gas chromatography-mass spectrometry.