scholarly journals Comparison of Micellar Electrokinetic Chromatography, Liquid Chromatography, and Microbiologic Assay for Analysis of Cephalexin in Oral Suspensions

2003 ◽  
Vol 86 (4) ◽  
pp. 707-713 ◽  
Author(s):  
Martin Steppe ◽  
María S Aurora Prado ◽  
Marina F M Tavares ◽  
Teresinha J A Pinto ◽  
Erika R M Kedor-Hackmann ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Micellar Electrokinetic Chromatography ◽  
Test Organism ◽  
Electrokinetic Chromatography ◽  
European Pharmacopoeia ◽  
Plate Method ◽  
Commercial Sample ◽  
Relative Standard ◽  
Routine Quality Control

Abstract Two well-accepted methodologies, based on a microbiologic assay (MA) and liquid chromatography (LC), and a novel methodology using micellar electrokinetic chromatography (MEKC), were compared for the determination of cephalexin in commercially available and simulated samples of oral suspensions. The MA, described in the BrazilianPharmacopeia, was performed with a strain of Staphylococcus aureus ATCC 6538 as the test organism, following the cylinder-plate method. The LC analysis followed the European Pharmacopoeia, 3rd Ed., and was used with minor modifications. The MEKC analysis was based on a previous work of the group. Estimates of the repeatability relative standard deviations of the MA, LC, and MEKC methods in the analysis of a commercial sample were 0.34, 0.42, and 0.37%, respectively. The recovery obtained with LC was 99.90 ± 1.11%; for MEKC, it was 100.09 ± 0.56%. Although the 3 methodologies were statistically equivalent for the determination of cephalexin in oral suspensions, MA gave suitable repeatability despite being nonspecific and time-consuming. MEKC provided faster analysis and higher column efficiency, whereas LC presented superior sensitivity. The results indicated that MEKC can be used as an alternative method to MA and LC in routine quality control laboratories.

scholarly journals A sweeping-micellar electrokinetic chromatography method for the detection of three chlorophenols in cosmetic samples

2020 ◽  
Author(s):  
Zhihan Zheng ◽  
Xiaobin Li ◽  
Fangfang Gao ◽  
Huitao Liu ◽  
Yuan Gao
Keyword(s):  
Micellar Electrokinetic Chromatography ◽  
Signal To Noise Ratio ◽  
Sodium Dodecyl ◽  
Electrokinetic Chromatography ◽  
Chromatography Method ◽  
Sample Matrix ◽  
Pressure Injection ◽  
Relative Standard ◽  
On Line

AbstractA sweeping micellar electrokinetic chromatography (sweeping-MEKC) enrichment model was established for the determination of three chlorophenols (CPs) in cosmetics, namely, bithionol, pentachlorophenol (PCP), and 2,4,6-trichlorophenol (2,4,6-TCP). The optimum electrophoretic conditions were 20 mM NaH2PO4-80 mM sodium dodecyl sulfate (SDS) and 30% (v/v) acetonitrile (pH 2.3). The optimum on-line concentration conditions were as follows: sample matrix, 100 mM NaH2PO4; pressure injection at 20.67 kPa (3 psi) for 25 s. The linear range of bithionol, PCP, and 2,4,6-TCP are 0.20–4.00 μg mL−1, 0.10–2.00 μg mL−1, and 0.05–2.00 μg mL−1 respectively, with correlation coefficient (r) over 0.9972. The limits of detection (LOD) based on three times the signal-to-noise ratio (S/N = 3) are in the range of 0.0061–0.024 μg mL−1. Recoveries for the three CPs in powder and lotion samples are between 79.7 and 110.2% with relative standard deviation (RSD) of 1.38–5.54% and 92.2–121.3% with RSD of 0.72–6.09%, respectively. The proposed method can provide reference for the determination of trace CPs in different sample matrix.

scholarly journals Microbiological Assay for Lomefloxacin in Coated Tablets

2006 ◽  
Vol 89 (4) ◽  
pp. 1077-1079 ◽  
Author(s):  
Greici Cristiani Gomes ◽  
Hérida Regina Nunes Salgado
Keyword(s):  
Bacillus Subtilis ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Method Validation ◽  
Test Organism ◽  
Microbiological Assay ◽  
Plate Method ◽  
Relative Standard ◽  
Bacillus Subtilis Atcc

Abstract The validation of a microbiological assay, applying cylinder plate method for determination of the activity of lomefloxacin in coated tablets is described. Using a strain of Bacillus subtilis ATCC 9372 as the test organism, lomefloxacin was measured in concentrations ranging from 2.0 to 8.0 μg/mL. The method validation showed that it is linear (r = 0.9999), precise (relative standard deviation = 1.15%), and accurate (it measured the added quantities). The excipients did not interfere in the determination. It was concluded that the microbiological assay is satisfactory for quantitation of lomefloxacin in tablets.

scholarly journals Determination of three phenoxyacid herbicides in environmental water samples by the application of dispersive liquid-liquid microextraction coupled with micellar electrokinetic chromatography

2013 ◽  
Vol 11 (3) ◽  
pp. 394-403 ◽  
Author(s):  
Yanling Ma ◽  
Yingying Wen ◽  
Jinhua Li ◽  
Hua Wang ◽  
Yangjun Ding ◽  
...  
Keyword(s):  
Water Samples ◽  
Micellar Electrokinetic Chromatography ◽  
Background Electrolyte ◽  
Environmental Water ◽  
Environmental Water Samples ◽  
Electrokinetic Chromatography ◽  
Relative Standard ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

AbstractAbstract An efficient method based on dispersive liquid-liquid microextraction coupled with micellar electrokinetic chromatography has been developed for determination of three phenoxyacid herbicides (PAs) of 2,4-dichlorophenoxybutyric acid (2,4-DB), dicamba and 2,4-dichlorophenoxyacetic acid (2,4-D), in environmental water samples. The types and volumes of extracting and dispersing solvents, ionic strength, extraction and centrifugation time and centrifugation speed were investigated. Successful separation of the three PAs was achieved within 7 min, by using the background electrolyte solution consisting of 10 mmol L−1 sodium tetraborate, 25 mmol L−1 sodium dodecyl sulfate and 15% (v/v) methanol, at pH 9.75. Excellent analytical performances were attained, such as good linear relationships (R ≥0.9993) between peak area and concentration for each PAs from 10–1000 ng mL−1, limits of detection of 1.56–1.91 ng mL−1, and intra-day precisions at two spiked levels in terms of migration time and peak area within the range of 0.22–0.42% and 3.88–6.39%, respectively. Enrichment factors of 2,4-DB, dicamba and 2,4-D were 180, 151 and 216, respectively. The method recoveries obtained at fortified 20.0, 50.0 and 100.0 ng mL−1 for lake, river and reservoir water samples varied from 67.91 to 119.07% with the relative standard deviation of 1.47–6.89%. Graphical abstract

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