Heroin abuse and a gas chromatographic method for determining illicit heroin samples in Singapore.

The abuse of heroin (diacetylmorphine) in Singapore escalated sharply in 1975 and 1976, as indicated by the 35-fold increase in the number of heroin seizures and the 20-fold increase in the urine samples containing morphine since 1974. A rapid and simple GC method has been described to estimate diacetylmorphine (and caffeine). Monoacetylmorphine and acetylcodeine may be ascertained by an additional step involving acetylation. All gas chromatograms of a large number of samples analyzed consistently had the same pattern, indicating that they possibly had a common origin. This GC "fingerprint," together with the quantitative data, appears to be characteristic of the illicit Asian or Chinese type of heroin found in Singapore. The proportions of the four major ingredients in some twelve typical samples have been tabulated. Statistical data confirming the accuracy and reproducibility of the analytical method have also been presented.     

Comparison analysis of illicit cocaine samples.

A rapid method for comparison analysis of illicit cocaine samples has been developed. The raw data are obtained by capillary gas chromatography using a nitrogen-phosphorus detector. The area ratios of four alkaloids (tropacocaine, norcocaine, cis-cinnamoylcocaine, and trans-cinnamoylcocaine) to cocaine are calculated for each sample. These ratios are compiled in a computer database which allows easy comparison of samples and makes possible reliable conclusions regarding their commonality of origin.     

One-step liquid-liquid extraction of cocaine from urine samples for gas chromatographic analysis

An improved technique for cocaine extraction from urine samples for gas chromatographic (GC) analysis is described. Employing a simple liquid-liquid extraction (LLE) of cocaine with a mixture of ethyl ether:isopropanol (9:1) the method presents a mean recovery of 74.49%. Limit of detection (LOD) and limit of quantification (LOQ) were 5 and 20 ng/ml, respectively. The method is highly precise (coefficient of variation (CV) <8%) and linear from 20 to 2000 ng/ml. It can he applied to detect the presence of cocaine in urine as a marker of its recent use in drug abuse treatment protocols.     

A rapid method for the determination of cocaine in brain tissue.

A rapid procedure is described for the extraction and analysis of brain samples for cocaine and benzoylecgonine. Human brain tissue was sectioned at autopsy, and samples were subjected to a lipase digestion, subsequent to solid-phase extraction. The distribution of cocaine and benzoylecgonine throughout different regions of the brain was determined by high-performance liquid chromatography.     

Capillary gas chromatographic analysis of illicit diamorphine preparations

An improved capillary gas chromatographic method for the analysis of illicit diamorphine preparation is reported. The method was able to resolve the impurities and more frequent adulterants and contaminants present in street heroin preparations with a diamorphine detection limit of 0.2 ng in split-less mode.     

A rapid method for the extraction of cocaine and benzoylecgonine from body fluids

A method has been developed for the rapid extraction of cocaine and benzoylecgonine from post-mortem blood and urine samples. Solid phase columns containing C8 packing material gave clean, emulsion free extracts from body fluids. The total time for each extraction was approx. 10 min and the system has the capacity for the simultaneous extraction of up to 10 samples. Urine can be extracted directly, blood samples were sonicated before extraction to allow for their easy passage through the columns. The method gave excellent recoveries of cocaine (98-100%) from spiked samples at concentrations of between 50 ng/ml and 10 micrograms/ml. Analysis of the extracts was by high performance liquid chromatography (HPLC).     

The examination of illicit cocaine

A laboratory system of examination of illicit cocaine exhibits is described. Separation and identification of many of the components in exhibits are achieved by the use of capillary column gas chromatography and a Finnigan ion trap detector. Further examination and quantitation of the components of exhibits is achieved using two high performance liquid chromatographic (HPLC) systems. Both of these systems use identical reverse phase C8 columns. System 1 employs a solvent composed of 40% acetonitrile, 10% tetrahydrofuran and 50% 0.1% v/v aqueous triethylamine. The eluant is monitored at 280 nm. This system is preferred for routine quantitative analysis of cocaine and related alkaloids in exhibits. System 2 employs a solvent composed of 30% acetonitrile and 70% 0.05M phosphate buffer (pH = 5.0). The eluant from this system is monitored at both 220 and 280 nm. This system offers advantages in sensitivity. The relative retention times of a number of relevant substances as determined with gas chromatography and the two HPLC systems are given. The utility of the methodology for the identification and comparison of exhibits is demonstrated.     

A gas chromatographic method for determining acetaldehyde in cadaver blood

Gas-chromatographic method of acetaldehyde detection in blood of subjects who died of alcoholic intoxication is suggested. Method is simple, does not require additional expenses, can be readily used in medicolegal practice and in difficult cases it may help the expert to make an objective conclusion on the cause of death.     

Cocaine profiling. A method of comparative substance studies of illegal cocaine samples]

Illegal cocaine were extracted in acidic medium. The extracts contain significant amounts of truxinic and truxillic acids. Successful comparism of cocaine out of different sources can be achieved by chromatographing trimethylsilyl- or dimethyl-t.-butylsilyderivates. The application of the method Ist limited by the purity of the samples.     

A gas chromatographic method for detecting nitrites in the blood and stomach contents

Ethyl nitrite method is proposed as the tentative test for nitrites in studies of the blood and gastric contents. The sensitivity of the method in "pure" solutions is 17 micrograms/sample. The method is specific and its sensitivity is not inferior to routine chemical analyses of biological materials for nitrites.     

Gas chromatographic method validation for the analysis of major components in illicit heroin seized in Malaysia

Apart from routine analysis of total morphine content required by the criminal justice system, quantification of other major components in illicit heroin has not been considered by the Malaysian enforcement laboratory. In order to quantify various other cutting agents in addition to alkaloids, a gas chromatographic (GC) method was developed to facilitate simultaneous quantification of eight target analytes commonly found in illicit heroin seized in Malaysia within a 12 min run time. The validation results demonstrated high selectivity with the use of an HP Ultra 2 capillary column. Different solvents were studied and methanol:chloroform (1:9) proved best for sample dissolution. The method was repeatable and reproducible. The study ranges covering 50-150% of the preferred concentrations of the eight analytes obtained r(2)>0.9997. Limits of detection up to 6μg/mL were also obtained and the method achieved 99-102% recovery. The capability of the method in heroin profiling was verified using samples from ten case samples.     

Development of a harmonised method for the profiling of amphetamines: III. Development of the gas chromatographic method

This study focused on gas chromatographic analysis of target compounds found in illicit amphetamine synthesised by the Leuckart reaction, reductive amination of benzyl methyl ketone, and the nitrostyrene route. The analytical method was investigated and optimised with respect to introduction of amphetamine samples into the gas chromatograph and separation and detection of the target substances. Sample introduction using split and splitless injection was tested at different injector temperatures, and their ability to transfer the target compounds to the GC column was evaluated using cold on column injection as a reference. Taking the results from both techniques into consideration a temperature of 250 degrees C was considered to be the best compromise. The most efficient separation was achieved with a DB-35MS capillary column (35% diphenyl 65% dimethyl silicone; 30 m x 0.25 mm, d(f) 0.25 microm) and an oven temperature program that started at 90 degrees C (1 min) and was increased by 8 degrees C/min to 300 degrees C (10 min). Reproducibility, repeatability, linearity, and limits of determination for the flame ionisation detector (FID), nitrogen phosphorous detector (NPD), and mass spectrometry (MS) in scan mode and selected ion monitoring (SIM) mode were evaluated. In addition, selectivity was studied applying FID and MS in both scan and SIM mode. It was found that reproducibility, repeatability, and limits of determination were similar for FID, NPD, and MS in scan mode. Moreover, the linearity was better when applying FID or NPD whereas the selectivity was better when utilising the MS. Finally, the introduction of target compounds to the GC column when applying injection volumes of 0.2 microl, 1 microl, 2 microl, and 4 microl with splitless injection respectively 1 microl with split injection (split ratio, 1:40) were compared. It was demonstrated that splitless injections of 1 microl, 2 microl, and 4 microl could be employed in the developed method, while split injection and splitless injections of 0.2 microl should be avoided.     

Comparative analysis of illicit heroin samples

The comparative analysis of street heroin samples is still an object of scientific discussion. A combination of a wide range of analytical techniques is necessary to obtain a valid amount of information about the sample composition, and it is impossible to define an unique analytical approach. We suggest a complete analytical sequence based on analysis of volatile compounds, opiates, diluents, adulterants and metals, by head space gas chromatography (HS/GC), gas chromatography mass spectrometry (GC/MS), thin layer chromatography (TLC), high pressure liquid chromatography (HPLC) and atomic absorption (AA) using a sample amount as low as 50-100 mg. The outlined procedure can be successfully applied to routine work, thus obtaining suitable information about a sample's chemical composition. This helps to attribute or exclude common sources of separate specimens. Results obtained on 33 street heroin samples confiscated in the metropolitan area of Rome are listed.     

Analytical studies on illicit heroin. II. Comparison of samples

A rapid method for the comparative analysis of illicit heroin samples has been developed. It is based on high pressure liquid chromatography using an ultraviolet and a fluorimetric detector simultaneously. The two detectors give so much information that reliable conclusions can be made.     

Headspace profiling of cocaine samples for intelligence purposes

A method for determination of residual solvents in illicit hydrochloride cocaine samples using static headspace-gas chromatography (HS-GC) associated with a storage computerized procedure is described for the profiling and comparison of seizures. The system involves a gas chromatographic separation of 18 occluded solvents followed by fully automatic data analysis and transfer to a PHP/MySQL database. First, a fractional factorial design was used to evaluate the main effects of some critical method parameters (salt choice, vial agitation intensity, oven temperature, pressurization and loop equilibration) on the results with a minimum of experiments. The method was then validated for tactical intelligence purposes (batch comparison) via several studies: selection of solvents and mathematical comparison tool, reproducibility and "cutting" influence studies. The decision threshold to determine the similarity of two samples was set and false positives and negatives evaluated. Finally, application of the method to distinguish geographical origins is discussed.