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See detailApplication of Total Error Strategy in Validation of Affordable and Accessible UV-Visible Spectrophotometric Methods for Quality Control of Poor Medicines
Mbinze, Kingenge; Nsangu Mpasi, Jean; Maghe, Elza et al

in American Journal of Analytical Chemistry (2015), 6

In the framework of fighting against the poor quality medicines sold in developing countries using classical analytical methods easily accessible in those countries, four UV-Visible spectrophotometric ... [more ▼]

In the framework of fighting against the poor quality medicines sold in developing countries using classical analytical methods easily accessible in those countries, four UV-Visible spectrophotometric methods for one antimalarial (quinine) and two antibiotics (amoxicillin and metronidazole) have been developed and validated according to the total error strategy using the accuracy profiles as a decision tool. The dosing range was 2-10µg/mL (for quinine sulfate in tablet), 4-12µg/mL (for quinine bichlorhydrate in oral drop - metronidazole benzaote in oral suspension) and 15-35µg/mL (for amoxicillin trihydrate in capsule). The validated methods were then applied in determining the content of some analogous medicines sold in the Democratic Republic of Congo. Thus, the proposed UV-Visible spectrophotometric methods are simple and suitable to quantify quinine, amoxicillin and metronidazole in different pharmaceutical forms. [less ▲]

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See detailFighting Poor Quality Medicines: Develop-ment, Transfer and Validation of Generic HPLC Methods for Analyzing two WHO Recommended Antimalarial Tablets
Mbinze Kindenge, Jérémie; Yemoa, Achille; Lebrun, Pierre ULg et al

in American Journal of Analytical Chemistry (2015), 6

As serious but neglected public health problems, poor quality medicines, i.e. for antimalarial medicines, urged to be fought. One of the approaches is to consider the analytical chemistry and separative ... [more ▼]

As serious but neglected public health problems, poor quality medicines, i.e. for antimalarial medicines, urged to be fought. One of the approaches is to consider the analytical chemistry and separative techniques. In this study, a generic liquid chromatographic method was firstly devel-oped for the purpose of screening 8 antimalarial active ingredients, namely amodiaquine (AQ), piperaquine (PPQ), sulfalene (SL), pyrimethamine (PM), lumefantrine (LF), artesunate (AS), artemether (AM) and dihydroartemisinine (DHA) by applying DoE/DS optimization strategy. Since the method was not totally satisfying in terms of peak separation, further experiments were undergone applying the same development strategy while splitting the 8 ingredients into five groups. Excellent prediction was observed prior to correlation between retention times of predicted and observed separation conditions. Then, a successful geometric transfer was realized to reduce the analysis time focusing on the simultaneous quantification of two WHO's recommended ACTs in anti-malarial fixed-dose combination (AM-LF and AS-AQ) in tablets. The optimal separation was achieved using an isocratic elution of methanol-ammonium formate buffer (pH 2.8; 10mM) (82.5: 17.5, v/v) at 0.6ml/min through a C18 column (100mm×3.5mm, 3.5 μm) thermostated at 25°C. After a successful validation stage based on the total error approach, the method was applied to determine the content of AM/LF or AS/AQ in seven brands of antimalarial tablets currently marketed in West, Central and East Africa. Satisfying results were obtained compared to the claimed contents. [less ▲]

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See detailA New Method for the Determination of Cyanide Ions and Their Quantification in Some Senegalese Cassava Varieties
Diallo, Younoussa; Gueye, Momar Talla; Ndiaye, Cheikh et al

in American Journal of Analytical Chemistry (2014), 5(3), 181-187

Cassava (Manihot esculenta Crantz) is a starchy staple food that previous researches have showed to contain cyanogenic compounds, precursors of hydrocyanic acid, undoubtedly toxic for humans. With the aim ... [more ▼]

Cassava (Manihot esculenta Crantz) is a starchy staple food that previous researches have showed to contain cyanogenic compounds, precursors of hydrocyanic acid, undoubtedly toxic for humans. With the aim to determine food security in cassava, this study developed a simple, fast and less expensive step for quantifying cyanide ions by using micro-diffusion with modified Conway cells. After an enzymatic degradation, the cyanide ions were quantified by electrochemical procedures. The validation of this method is estimated. The concentration of cyanide ions at different part of the samples was determined. The results showed high toxicity in some fresh Senegalese consumed cassava varieties (>100 mg HCN·kg﹣1). However, in the processed cassava products, less than 10 mg HCN·kg﹣1 was found in the different varieties studied except for the chips where the levels of CN﹣ contents were important (>49 mg HCN·kg﹣1). [less ▲]

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See detailDevelopment of a performant method for glucocapparin determination in Boscia senegalensis Lam ex. Poir. : A study of the variability
Gueye, Momar Talla; Seck, Dogo; Diallo, Abdoulaye et al

in American Journal of Analytical Chemistry (2013), 4

This study describes a glucocapparin determination method. Based on rapeseed determination of glucosinolate (GSL), the equation of the average straight regression line is Y = 100.42X − 0.03 (R2 = 0.9998 ... [more ▼]

This study describes a glucocapparin determination method. Based on rapeseed determination of glucosinolate (GSL), the equation of the average straight regression line is Y = 100.42X − 0.03 (R2 = 0.9998). Enzymatic hydrolysis of glucocapparin extracted from leaves and fruits of B. senegalensis, analyzed by SPME-GC-MS confirmed the presence of methylisothiocyanate as the main hydrolysis glucocapparin product. Monitoring glucocapparin contents in B. senegalensis leaves and fruits collected in 4 localities in Senegal showed differences between organs according localities and periods of harvest. Glucocapparin content was very high in dry season particularly in January and the lowest rates were recorded during the rainy period between August and November. [less ▲]

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See detailFast-GC quantifacation of harmonine, the major defense alkaloid of the multicolored Asian ladybird Harmonia axyridis (Pallas)
Fischer, Christophe ULg; Laurent, Pascal ULg; Heuskin, Stéphanie ULg et al

in American Journal of Analytical Chemistry (2012), 3

These last few years the multicolored Asian ladybird, Harmonia axyridis (Pallas), previously introduced in Europe and North America as a biological control agent, has swiftly spread out on those ... [more ▼]

These last few years the multicolored Asian ladybird, Harmonia axyridis (Pallas), previously introduced in Europe and North America as a biological control agent, has swiftly spread out on those territories and turns out to be a pest in several ways. In order to improve understanding of several key points of the biology of this ladybird, a novel fast-GC method of quantification of harmonine, the main defense alkaloid of H. axyridis, has been designed and validated using the accuracy profile concept for concentrations ranging from 13 to 264 µg/individual. This method allows quantifying harmonine in a single insect with a maximal error risk of 20%. For ladybirds collected in spring, mean harmonine concentration observed was 106.6 µg/individual with a very high standard deviation of 80.2 µg/individual, which can easily be explained by the strong asymmetry of the results distribution. Males and females seem equally chemically protected as the harmonine concentration did not significantly differ between sexes. This method is currently used to improve our comprehension of several key points of H. axyridis biology including aggregation behavior and aposematism. [less ▲]

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See detailFast-GC quantification of harmonine, the major defense alkaloid of the multicolored asian ladybird Harmonia axyridis (Pallas)
Fischer, Christophe ULg; Laurent, P; Heuskin, Stéphanie ULg et al

in American Journal of Analytical Chemistry (2012), 3

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