Tropane Ethyl Esters in Illicit Cocaine: Isolation, Detection, and Determination of New Manufacturing By‐Products from the Clandestine Purification of Crude Cocaine Base with Ethanol

Abstract

Seven ethyl homologues of known tropane esters have recently been detected as impurities in the gas chromatographic signature profiles of authentic Peruvian illicit cocaine base and hydrochloride exhibits. Peruvian cocaine base processors are now known to use ethanol for the purification of crude cocaine base. This process is referred to as the "base lavada" or "washed base" process and is a recent substitute method for the potassium permanganate oxidation purification methodology. Seven ethyl ester homologues were formed in illicit cocaine from the transesterification of known tropane methyl esters or possibly ethyl esterification of their respective tropane C-2 carboxylic acids in the presence of ethanol. Exhibits containing these compounds were subjected to gas chromatographic-mass spectrometric analyses to determine their identity and were subsequently synthesized to verify their structures. Quantitative determinations were obtained from ion-pair chromatography isolation followed by gas chromatography with flame ionization detection. Specifically, hexanoylecgonine ethyl ester, cocaethylene, cis-cinnamoylecgonine ethyl ester, trans-cinnamoylecgonine ethyl ester, 3',4',5'-trimethoxybenzoylecgonine ethyl ester, cis-3',4',5'-trimethoxycinnamoylecgonine ethyl ester, and trans-3',4',5'-trimethoxycinnamoylecgonine ethyl ester were detected and characterized. When present, these compounds were detected at levels ranging from 8.6 x 10(-4) to 9.3 x 10(-1)% relative to cocaine.

Applicability of ultra‐high performance liquid chromatography‐quadrupole‐time of flight mass spectrometry for cocaine profiling

“…First, a preliminary screening of other minor alkaloids reported in literature [13][14][15][16][17][18][19] was applied on the control sample. However, the low detection limits of UHPLC-Q-TOF enable the detection of minor impurities without complicated sample preparation procedures.…”

“…The use of profiling methods has been shown to produce powerful means of establishing links between seizures, thus providing drug intelligence. [13][14][15][16][17][18][19][20] The nine most abundant beings are ecgonine, ecgonine methyl ester, tropacocaine, cocaine, norcocaine, benzoylecgonine, cis-/transcinnamoylcocaine, and 3,4,5-trimethoxycocaine [3,4,8] ; other minor constituents such as ecgonidine methyl ester, 3,4,5-trimethoxycis-/trans-cinnamoylcocaine, cis-/trans-cinnamoylecgonine, also appear but in relatively low levels. Among them, the alkaloid profiling method has gained most wide application.…”

“…[2] The chemical profile of cocaine can be based on alkaloid impurities, [3][4][5][6][7][8][9] occluded solvents, [10] stable isotopes, [11,12] and others. [13][14][15][16][17][18][19] Some alkaloids come from coca leaf and are co-extracted with cocaine; others result from a hydrolysis, an oxidation or a thermo-degradation of cocaine during its producing. Casale and Moore et al began to study alkaloids in cocaine and coca leaf in the 1970s, and reviewed the profiling analysis of cocaine and its precursors.…”

Detection of cocaine and its metabolites in urine using solid phase extraction-ion mobility spectrometry with alternating least squares

“…When people consume cocaine with alcohol, a different metabolite, cocaethylene, is produced and should also be tested in screenings. Cocaethylene may also be produced from the cocaine production process due to the recrystallization step which uses ethanol, or from the transport process when cocaine is sometimes smuggled dissolved in ethanol [2]. Because of the highly hydrophilic nature of benzoylecgonine, other water-soluble metabolites in urine may interfere with its extraction, increasing the background noise and generating interfering signals.…”

Alcohol Biomarkers in Hair

“…On the other hand, a positive CE result despite negative EtG or FAEE can occur in cases of moderate alcohol use concurrent to frequent cocaine use or if the illicit cocaine contained CE which is formed in certain manufacturing procedures with alcohol as the solvent [171]. A high EtG or FAEE concentration without detection of CE could mean that alcohol and COC are not or only occasionally used together, that COC results only from external contamination or that COC and CE are less efficiently incorporated in nonpigmented hair.…”