Volume 8, Issue 5

Mauritius is presently witnessing a major educational reform, which has necessitated a review of the lower secondary curriculum in all subjects, including Science. Educators were called to evaluate the Science curriculum (which includes Biology, Chemistry and Physics components) by providing feedback on the curriculum content and content organisation. One hundred and thirty-three educators took part in this exercise. This paper focuses on a detailed analysis of the feedback obtained from educators regarding the lower secondary Chemistry curriculum (LSCC) to identify the challenges encountered in its implementation. The Process component of the Stufflebeam’s (Stufflebeam DL. The CIPP model for evaluation. In: Evaluation models. Dordrecht: Springer; 2000:279–317 pp) Context, Input, Process and Product (CIPP) Evaluation model has been used as a framework for the study. Based on qualitative thematic analysis, four main challenges were identified in the implementation of the LSCC namely, ensuring curriculum continuity, avoiding curriculum overload, the need for more laboratory experiences and knowledge transfer.

Polymers are excellent materials that provide concrete examples of concepts and learning objectives covered in different post-secondary level courses. Modules focused on polymer science can be used for teaching general, organic, material and green chemistry. These modules can be tailored to build on the students' prerequisite knowledge. Science 300 is a course offered at Simon Fraser University (SFU) to non-science, post-secondary students focused on the impact of science in society. Prosthetics and Orthotics (PROR) is a diploma program offered at the British Columbia Institute of Technology (BCIT). Both programs have incorporated polymer science as part of the curriculum. Design of the modules illustrates polymers as an important class of materials that possess both beneficial and environmental unfriendly properties. A variety of learning strategies are incorporated within the courses to aid students with understanding polymer science.

A comparison was carried out between quadrupole inductively coupled plasma mass spectrometry (ICP-QMS) detection and sector field ICP-MS (ICP-SFMS) detection for quantification of elements such as arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn), and uranium (U) in drinking water. A drinking water sample obtained from the International Atomic Energy Agency was used for validation measurement methods. ICP-QMS and ICP-SFMS obtained recoveries of 95–107% and 95–105%, respectively. Moreover, the relative standard deviation for ICP-QMS was <5% in comparison with ICP-SFMS, which was <2%. The limits of detection obtained in ICP-MS and ICP-SFMS for each element were under ng L −1 , except for Zn. Both methods were applied to evaluate these elements in drinking water for consumption in Mexico. According to Mexican Regulation for Human Drinking Water NOM-201-SSA1-2015 and Environmental Protection Agency (EPA) from the United States, the values are within the allowable limits. In conclusion, ICP-QMS and ICP-SFMS are excellent choices for measurements of these toxic elements in water samples because of high precision and accuracy in routine analysis minutes, while also exhibiting excellent precision and accuracy in routine analysis.

The aim of the study was to develop a rapid, efficient, and cheap chromatographic method for determining four selected antihypertensive active flavonoid compounds in medicinal plants in Botswana. The determination of rutin, quercetin, and kaempferol in selected medicinal plants was conducted in less than 6 min using the developed reverse phase-high performance liquid chromatography (RP-HPLC) method with a 2.7 µm Ascentis C18 express column (150 × 4.60 mm i.d) at 340, 360, and 368 nm detection wavelengths and mobile phase of methanol and 0.068% of formic acid solution in isocratic elution. Validation results showed good selectivity, linearity ( r 2  > 0.99), high percentage recoveries (90.2–104.7%), and precision (% RSD < 2) for n  = 3, confirming suitability of the method for determination of the investigated flavonoids in Zingiber officinale (ginger). Application of the developed RP-HPLC method was performed in selected medicinal plants ( Lippia javanica ) (mosukujane) , Myrothanmus flabellious (galalatshwene) , and Elephantorrhiza elephantina (mositsana) used to manage hypertension by herbalists in Botswana . M. flabellious a very commonly used plant for managing hypertension was found to contain highest amounts of rutin and myricetin, whereas nothing was detected for E. elephantina .

The contamination of water sources as a result of man’s activities is of concern because of its potential impact on the health of humans. Samples of groundwater were collected from four households within metropolitan Lagos between the months of April and August, 2019. The samples were analyzed for cadmium, calcium, iron, lead, manganese and zinc using atomic absorption spectrometry. Structured questionnaire was administered to the residents in households where the water samples were collected. Results obtained were compared with global background values and WHO guidelines for drinking water. The pH values ranged from 5.16 ± 0.26 to 5.29 ± 0.44, whereas, the control pH values were within the WHO guidelines of 6.5–8.5. The concentrations (mg/L) ranged from 2.04 ± 1.01–23.48 ± 8.81 (calcium); 3.35 ± 1.94–3.60 ± 2.25 (iron); 0.31 ± 0.42–0.47 ± 0.51 (manganese) and 0.27 ± 0.04–0.77 ± 0.69 (zinc), respectively. Cadmium and lead were not detected. The health risk indices (HRI) values were found to be in the order of Fe > Zn > Mn and were below the threshold value of 1. Statistical analysis of variance (ANOVA) was used to ascertain statistical significant differences of metal concentrations in the four locations. Metal pollution source control and periodic water quality monitoring is recommended.

Cadaba farinosa is used in traditional medicine for treatment of cancer, diabetes, and rheumatism. The research was aimed at evaluating the phytochemical and antioxidant activity of the extracts. The powdered stem bark was extracted successively with the aid of Soxhlet extractor using n-hexane, ethyl acetate, and methanol. The resulting extracts were concentrated on rotary evaporator and the percentage yields were calculated. The phytochemical and TLC profiles of the extracts were studied. The antioxidant activity of the extracts and ascorbic acid (standard) were determined using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. The total phenolic content of the extracts and tannic acid (standard) were evaluated using Folin–Ciocalteu reagent. The percentage yields of n-hexane, ethyl acetate, and methanol extracts were found to be 1.19, 1.37, and 13.93%, respectively. The phytochemical screening revealed the presence of tannins, flavonoids, saponins, cardiac glycosides, alkaloids, and triterpenoids. The TLC profiles of the extracts revealed the presence of compounds as evidenced from their R f values. The total phenolic content of ethyl acetate and methanol extracts were found to be 135 and 112 mg, respectively. The free radical scavenging activity demonstrated by the extracts was comparable to ascorbic acid. The ethyl acetate extract had higher phenolic content and demonstrated the highest free radical scavenging with IC 50 31.07 mg/mL. The results of research have provided strong preliminary evidence of antioxidant activity which may be because of phenolic compounds in the extracts.