Lawrence Mzukisi Madikizela

Determination of ibuprofen, naproxen and diclofenac in aqueous samples using a multi-template molecularly imprinted polymer as selective adsorbent for solid-phase extraction

This study describes the application of multi-template molecularly imprinted polymer (MIP) as selective sorbent in the solid-phase extraction (SPE) of naproxen, ibuprofen and diclofenac from wastewater and river water. MIP was synthesized at 70°C by employing naproxen, ibuprofen and diclofenac as multi-templates, ethylene glycol dimethacrylate, 2-vinyl pyridine and toluene as cross-linker, functional monomer and porogen, respectively. Wastewater and river water samples (pH 2.5) were percolated through SPE cartridge packed with 50mg of the MIP. The cartridge was washed with 2mL of methanol-water 10:90% (v:v) prior to elution with 2mL of acetic acid-acetonitrile 20:80% (v:v). Quantification of eluted compounds was performed with high performance liquid chromatography equipped with photo diode array detection. The detection limits were 0.15, 1.00 and 0.63μgL(-1) for naproxen, ibuprofen and diclofenac, respectively. Recoveries for naproxen, ibuprofen and diclofenac in deionized water spiked at 5 and 50μgL(-1) were greater than 80%. Ibuprofen was the most frequently detected compound with maximum concentrations of 221, 67.9 and 11.4μgL(-1) in wastewater influent, effluent and river water, respectively.

Status of pharmaceuticals in African water bodies: Occurrence, removal and analytical methods

In this review paper, the milestones and challenges that have been achieved and experienced by African Environmental Scientists regarding the assessment of water pollution caused by the presence of pharmaceutical compounds in water bodies are highlighted. The identification and quantification of pharmaceuticals in the African water bodies is important to the general public at large due to the lack of information. The consumption of pharmaceuticals to promote human health is usually followed by excretion of these drugs via urine or fecal matter due to their slight transformation in the human metabolism. Therefore, large amounts of pharmaceuticals are being discharged continuously from wastewater treatment plants into African rivers due to inefficiency of employed sewage treatment processes. Large portions of African communities do not even have proper sanitation systems which results in direct contamination of water resources with human waste that contains pharmaceutical constituents among other pollutants. Therefore, this article provides the overview of the recent studies published, mostly from 2012 to 2016, that have focused on the occurrence of different classes of pharmaceuticals in African aqueous systems. Also, the current analytical methods that are being used in Africa for pharmaceutical quantification in environmental waters are highlighted. African Scientists have started to investigate the materials and remediation processes for the elimination of pharmaceuticals from water.

Applications of molecularly imprinted polymers for solid-phase extraction of non-steroidal anti-inflammatory drugs and analgesics from environmental waters and biological samples

HighlightsWe reviewed the common reagents used in synthesis of molecularly imprinted polymers for NSAIDs and analgesics.We reviewed the molecularly imprinted solid‐phase extraction applications for NSAIDs and analgesics.We focused on molecularly recognition mechanism and selectivity of MIPs for NSAIDs and analgesics.Challenges and future opportunities in the synthesis and applications of MISPE for NSAIDs and analgesics are given. ABSTRACT The occurrence of pharmaceuticals used as non‐steroidal anti‐inflammatory drugs (NSAIDs) and analgesics in the aquatic environment is a threat to humans and aquatic species at large. The primary route of these pharmaceuticals to aquatic environment is through human waste such as urine and faeces. The application of molecularly imprinted polymers (MIPs) in the solid‐phase extraction (SPE) of such pollutants from environmental and biological samples is important for the pre‐concentration of compounds and selectivity of the analytical methods. To date, there are still limited commercial suppliers of MIPs. However, it is easy to synthesize such polymers via non‐covalent imprinting approach using easily available and affordable reagents. Therefore, the applications of MIPs in the SPE of NSAIDs and analgesics from environmental and biological samples are reviewed. This is very important because despite the fact that review articles on applications of MIPs for organic compounds have been reported, very little has focussed on NSAIDs and analgesics which are the major studied pharmaceuticals in the environment and biological samples. The review also brings out important aspects of common reagents used including the template molecules during MIP synthesis. Application and future trends are also discussed. Gaps such as little use of environmental friendly reagents such as ionic liquids have been identified. Also, the lack of MIP applications to some compounds such as fenoprofen has been observed which is likely to be developed in the near future.

Uptake of pharmaceuticals by plants grown under hydroponic conditions and natural occurring plant species: A review

Sizeable amount of research has been conducted on the possible uptake of pharmaceuticals by plants from contaminated soil and water used for irrigation of crops. In most cases, pharmaceuticals are taken by roots and translocated into various tissues by transpiration and diffusion. Due to the plant uptake, the occurrence of pharmaceuticals in food sources such as vegetables is a public concern. Few review papers focusing on the uptake of pharmaceuticals, in particular antibiotics, and their translocation in plant tissues have been published. In the current review paper, the work conducted on the uptake of pharmaceuticals belonging to different therapeutic groups such as antibiotics, non-steroidal anti-inflammatory drugs, β-blockers and antiepileptics is reviewed. Such work includes the occurrence of pharmaceuticals in plants, translocation once taken by plants, toxicity studies as well as implications and future studies. Furthermore, the advantages and drawbacks associated with the detection and uptake of these pharmaceuticals by plants are discussed. In addition, the physico-chemical properties that could influence the plant uptake of pharmaceuticals are deliberated.

Google Analytics and quick response for advancement of gold nanoparticle-based dual lateral flow immunoassay for malaria – Plasmodium lactate dehydrogenase (pLDH)

A rapid dual lateral flow diagnostic assay fabricated with quick response (QR) barcodes was developed to improve the quality control of malaria diagnostic tests, as well as to enhance systems for transferring data from survey studies among community healthcare workers at a point-of-care facility and centralized laboratories. The lateral flow kit has been modified with QR technology encoded with Google Analytics information for the detection and real-time tracking of Plasmodium lactate dehydrogenase (pLDH). The QR barcode was fabricated by attaching two QR barcodes which were encoded with websites that were linked to Google Analytics. The optical and structural properties of gold nanoparticles (AuNPs) were studied using UV-visible spectroscopy, transmission electron microscopy and a Biodot XYZ. The anti-mouse IgG antibody was used as a secondary antibody to act as a control and anti-pLDH. The antibody binding with pLDH antigens shows a test line indicating a positive test in the presence of phosphate buffer as a mobile phase. The diagnostic kit for the rapid detection of pLDH was developed and validated for the detection of malaria antigens at the lowest detectable recombinant concentration of 10 ng ml−1. The diagnostic kit was incorporated with quick QR barcodes for positive, negative and invalid tests readable with a smartphone. These QR barcodes successfully allowed us to track the precise location of the test through Google Analytics.

Environmental fate and ecotoxicological effects of antiretrovirals: A current global status and future perspectives

The therapeutic efficacy of antiretroviral drugs as well as challenges and side effects against the human immunodeficiency virus is well documented and reviewed. Evidence is available in literature indication that antiretrovirals are only partially transformed and become completely excreted from the human body in their original form and/or as metabolites in urine and feces. The possibility of massive release of antiretrovirals through human excreta that enters surface water through surface runoff and wastewater treatment plant effluents is now of environmental concern because the public might be experiencing chronic exposure to antiretrovirals. The primary concern of this review is limited data concerning environmental fate and ecotoxicity of antiretrovirals and their metabolites. The review aims to provide a comprehensive insight into the evaluation of antiretrovirals in environmental samples. The objective is therefore to assess the extent of analysis of antiretrovirals in environmental samples and also look at strategies including instrumentation and predictive models that have been reported in literature on the fate and ecotoxicological effects due to presence of antiretrovirals in different environmental compartments. The review also looks at current challenges and offers possible areas of exploration that could help minimize the presence of antiretrovirals in the environment.