A simple and rapid external standard calibration HPLC method for determination of lumefantrine in dried blood spot samples from malaria patients in Botswana.

A simple external calibration liquid chromatography-diode array detector method was developed, validated, and applied for the determination of lumefantrine (Lum) in dried blood spot (DBS) samples collected from malaria patients in Botswana. The samples were validated in accordance with the United States Food and Drug Administration guidelines for bioanalytical methods after sample preparation using solid-liquid extraction. Separation was achieved using an XTerra C18 column (50 × 4.

A solid-phase microextraction gas chromatography-mass spectrometry technique for urinary metabolomics of human samples infected with schistosomiasis-Case of the Okavango Delta, Botswana.

We present a GC-MS metabolomics workflow for analyzing metabolites in urine samples infected with schistosomiasis. Schistosomiasis, a neglected tropical disease, affects 85% of the global population, with the majority residing in Sub-Saharan Africa. The workflow utilized in this study involved the utilization of the AMDIS freeware, Metab R for pre-processing, and multivariate statistical classification through partial least squares-discriminant analysis (PLS-DA).

Polychlorinated dibenzo-p-dioxin/dibenzofurans (PCDD/Fs) contamination in sediments and fish from Msimbazi River in Dar es Salam, Tanzania: patterns, sources, and their exposure to humans.

Results of a two-dimensional gas chromatograph time of flight mass spectroscopy (GCXGC-TOFMS) determination of polychlorinated dibenzo-p-dioxin (PCDDs) and polychlorinated dibenzofurans (PCDF) in sediments and catfish samples collected from the Msimbazi River are presented here. Samples were extracted using USEPA Method 1613. PCDD/Fs congeners in sediments ranged from 2.

Untargeted GC-MS metabolomics to identify and classify bioactive compounds in Combretum platypetalum subsp. oatesii (Rolfe) Exell (Combretaceae).

Introduction: Combretum platypetalum is used in traditional African healing practices against different infections. Unfortunately, no scientific knowledge of its phytochemical composition exists, except for the isolation of two compounds from the leaves. Scientific study has been limited to the leaves only, despite the applications of stems and roots in traditional medicine practice and natural product drug discovery programs.

Mass spectrometry based metabolomics for small molecule metabolites mining and confirmation as potential biomarkers for schistosomiasis - case of the Okavango Delta communities in Botswana.

Introduction: Metabolomics for identifying schistosomiasis biomarkers in noninvasive samples at various infection stages is being actively explored. The literature on the traditional detection of schistosomiasis in human specimens is well documented. However, state-of-the-art technologies based on mass spectrometry have simplified the use of biomarkers for diagnostics.

A fast-screening dispersive liquid-liquid microextraction-gas chromatography-mass spectrometry method applied to the determination of efavirenz in human plasma samples.

We demonstrate the suitability of a fast, green, easy-to-perform, and modified sample extraction procedure, i.e., dispersive liquid-liquid microextraction (DLLME) for the determination of efavirenz (EFV) in human plasma.

Mapping polychlorinated dibenzo-p-dioxins/dibenzofurans in soils around Pugu municipal dump site in Dar es Salaam, Tanzania: Implications on dermal and soil ingestion exposure for people in the peripheral.

Experimental data on the contribution of a dump site in Tanzania as a point source of the 17 possible congeners of PCDD/Fs to the environment is presented. Dry and wet season samples were collected around Pugu municipal dump site followed by GCxGC-TOFMS analysis. The dominant congeners were OctaCDD, 1,2,3,4,6,7,8-HepCDF; 1,2,3,4,6,7,8-HeptaCDD and 1,2,4,7-PeCDD.

Comparison of Soxhlet and reflux techniques for extraction and characterisation of potential endocrine-disrupting compounds from solid waste dumpsite soil.

Landfill leachate contains a myriad of hazardous chemicals; as such, they should always be planned and constructed following approved guidelines. A sample of soil collected from the old quarry designated as the official solid waste disposal site in Maseru, the capital city of Lesotho, was exposed to two extraction techniques, namely Soxhlet and reflux extractions, for characterisation of the potential endocrine-disrupting chemicals in the leachate. Principal component analysis was used to compare the extractability of these chemicals between the two methods, and it revealed that phthalates extract better in Soxhlet than in reflux extraction.

Monitoring polychlorinated dibenzo-p-dioxins/dibenzofurans and dioxin-like polychlorinated biphenyls in Africa since the implementation of the Stockholm Convention-an overview.

Polychlorinated dibenzo-p-dioxin (PCDDs), polychlorinated dibenzofurans (PCDF), and dioxin-like polychlorinated biphenyl (dl-PCB) are groups of toxic compounds released into the environment as unintentional by-products of combustion. They persist, bioaccumulate through the food chain, and cause adverse health effects. This review attempts to collate available information on the release of PCDD/Fs and dl-PCBs and other critical data relevant to their monitoring in Africa during the existence of the Stockholm Convention (SC).

Comparison of efficiencies of selected sample extraction techniques for the analysis of selected antiretroviral drugs in human plasma using LC-MS.

Introduction: Sample preparation in bio analytical chemistry poses a challenge because it can be compound dependent. We compared six sample extraction techniques i.e.

Assessment of Heavy-Metal Pollution in Sediments and Tilapia Fish Species in Kafue River of Zambia.

We report results from an evaluation of the levels of heavy metals, i.e., copper (Cu), cadmium (Cd), lead (Pb), nickel (Ni), manganese (Mn), chromium (Cr), and iron (Fe) in sediment and tilapia fish samples from a wide stretch of the Kafue river of Zambia.

Linking environmental exposure with public health: dichlorodiphenyltrichloroethane extracted from soils and water of recently exposed communities of selected locations in Zambia.

Background: In 2000, a Zambian private mining company reintroduced the use of dichlorodiphenyltrichloroethane (DDT) to control malaria in two districts. From 2000 to 2010, DDT had been applied in homes without any studies conducted to ascertain its fate in the environment. We aimed to quantify the presence of DDT and its metabolites in the soil and water around communities where it was recently used.

An Investigation of Liquid Chromatography-Mass Spectral Attributes and Analytical Performance Characteristics of Tenofovir, Emtricitabine and Efavirenz in Human Plasma.

Liquid chromatography (LC) and mass spectral behavior and analytical performance characteristics of efavirenz (EFV), emtricitabine (EMT) and tenofovir (TFV), i.e., individual components of Atripla(®), were probed.

Comparative chromatography-mass spectrometry studies on the antiretroviral drug nevirapine-analytical performance characteristics in human plasma determination.

A contrast between the analytical performance characteristics using gas chromatography-mass spectrometry (GC-MS) liquid chromatography-mass spectrometry (LC-MS) and liquid chromatography-ultraviolet (LC-UV) detection for the determination of the antiretroviral drug (ARV) nevirapine (NVP) in fortified human plasma after QuEChERS extraction has been made. Analytical performance characteristics, i.e.

GC-MS determination of targeted pesticides in environmental samples from the Kafue Flats of Zambia.

Results of a GC-MS analysis for targeted pesticides i.e. dieldrin, endosulfan, pp-DDT, endrin, HCB, heptachlor, mirex and aldrin in the Kafue Flats of Zambia are presented.

Pre-electrospray ionisation manifold methylation and post-electrospray ionisation manifold cleavage/ion cluster formation observed during electrospray ionisation of chloramphenicol in solutions of methanol and acetonitrile for liquid chromatography-mass spectrometry employing a commercial quadrupole ion trap mass analyser.

We have observed unusual mass spectra of chloramphenicol (CAP) in solutions of methanol or acetonitrile showing intense ions at m/z 297, m/z 311, m/z 325 and m/z 339. The observed ions were different from those which are traditionally observed in the full scan ESI mass spectra of CAP with ions of m/z 321, m/z 323 and m/z 325. We have evidence to show that this process starts with offline methylation of CAP in solutions of methanol or acetonitrile to give m/z 339.

Evaluation of endocrine disruptor levels in Kafue Lechwe (Kobus leche kafuensis) samples from the Blue Lagoon National Park of Zambia.

The concentrations of endocrine disruptors were determined in 36 liver tissue, serum and whole blood sample extracts drawn from 15 Blue Lagoon National Park Kafue lechwe. Out of 10 analytes evaluated, 89% of the sample extracts showed very high dieldrin concentrations of between 0.08–100 μg/mL in serum, 0.

Determination of endocrine disruptors in Kafue lechwe (Kobus leche kafuensis) samples from the Lochinvar National Park of Zambia.

Analysis of serum, whole blood and liver tissue samples from Kafue lechwe in the Lochinvar National Park of Zambia for suspected endocrine disrupting compounds revealed high concentrations for some of the compounds. 45 samples of serum, whole blood and liver tissue were extracted by liquid-liquid extraction followed by an analysis using Gas Chromatography-Electron Capture Detection (GC-ECD). The following endocrine disruptors were analyzed: deltamethrin, aldrin, endosulfan, dieldrin, pp-DDD, heptachlor, d-t-allethrin, pp-DDE, endrin and pp-DDT.

Analysis of the level of comprehension of chemical hazard labels: a case for Zambia.

We have surveyed the impact of chemical hazard label elements on four target sectors, i.e. the agricultural, industrial, transport and the consumer (the general public) sectors, in order to assess the type of reactions the respondents perceive to a given chemical label element such as symbol, hazard phrase, color, and hazard signal word.

Distribution of copper, lead, cadmium and zinc concentrations in soils around Kabwe town in Zambia.

The extent of pollution of the environment as a result of mining activities in Kabwe, the provincial capital of Central province in Zambia has not yet been evaluated. Mining of lead and zinc were the core activities of Kabwe mine while cadmium and silver were produced as by-products. The smelting processes produced a significant amount of copper.

Enhanced signal generation for use in the analysis of synthetic pyrethroids using chemical ionization tandem quadrupole ion trap mass spectrometry.

Synthetic pyrethroids fragment extensively under electron ionization (EI) conditions to give low mass ions, most of them with the same m/z ratios. This fragmentation is primarily due to the labile ester linkage found in these compounds. In this research we established the best gas chromatography (GC) conditions in the EI mode that served as a benchmark in the development of a chemical ionization (CI) protocol for ten selected synthetic pyrethroids.