A validated method for the analysis and profiling of ‘nyaope’ using gas chromatography – mass spectrometry

Pabalala M. Mthembi; Ellen M. Mwenesongole; Michael D. Cole

doi:10.17159/sajs.2021/8738

Authors

Pabalala M. Mthembi 1.Department of Genetics, University of the Free State, Bloemfontein, South Africa; 2.South African Police Service Forensic Science Laboratory – Chemistry Section, Pretoria, South Africa https://orcid.org/0000-0001-9045-4329
Ellen M. Mwenesongole 1.Department of Genetics, University of the Free State, Bloemfontein, South Africa; 2.Department of Chemical and Forensic Sciences, Botswana International University of Science and Technology, Palapye, Botswana https://orcid.org/0000-0002-5121-2623
Michael D. Cole Faculty of Science and Engineering, Anglia Ruskin University, Cambridge, United Kingdom https://orcid.org/0000-0001-7155-3102

DOI:

https://doi.org/10.17159/sajs.2021/8738

Keywords:

heroin, cannabis, nyaope, GC–MS, sample comparison

Abstract

Nyaope, a Tswana word for a mixture or ‘mish-mash’, describes a drug cocktail consisting of heroin, cannabis, and on occasion other controlled substances and warfarin. It is highly addictive with extremely unpleasant side effects caused by withdrawal from the drug. It is a problem drug especially in townships in South Africa. However, its prevalence in neighbouring southern African states and further afield is not yet known. There is currently no validated method for the analysis and comparison of nyaope. We describe a validated method for the gas chromatography – mass spectrometry analysis of nyaope so that within-batch and between-batch comparisons of nyaope can successfully be made for the first time. The validated method managed an accuracy within the range 80–120%, the precision was less than 20% for all analytes and managed linearity with R²≥0.99. The detection limits for diamorphine, efavirenz, nevirapine and Δ9-tetrahydrocannabinol were 14.2, 18.6, 18.7 and 9.94 pg on column, respectively, and the limits of quantitation were 43.1, 56.3, 56.6 and 30.1 pg on column, respectively. The simulated and casework samples were successfully discriminated into original batches using the identified nyaope components, the unsupervised chemometric methods principal component analysis and hierarchical clustering, as well as chromatographic profiles.

Significance:

A validated method for the analysis and comparison of nyaope allows for data exchange between law enforcement agencies in South Africa and, provided the appropriate quality control measures are in place, between South Africa, neighbouring states and countries further afield. Additionally, public health measures can be put in place now that it is possible to use a validated method to determine the contents of nyaope.