High Performance Liquid Chromatographic Analyses of Sulphonamides and Dihydrofolate Reductase Inhibitors. IV. Recoveries from the Stationary Phase, Quantitation and Sensitivities

Abstract

Of the twenty-two sulphonamides and three commonly used dihydrofolate reductase inhibitors investigated for reverse phase separation in previous studies, the recoveries of five representative drugs from the stationary phase have been examined. Sulphanilamide, sulfisomindine, sulphaquinoxaline, diaveridine and pyrimethamine were chosen. Peak areas off the analytical column were compared with those obtained by substitution with stainless steel tubing. After careful correction for flow rate differences where necessary, 100% recoveries were indicated. As a further check, Maloprim tablets were assayed for pyrimethamine and the analysed results were found to be (99.1 f 3155 COpyight C 1996 by Marcel Dekker, Inc. Downloaded by [Michigan State University] at 23:01 08 February 2015 3 156 RICCI AND CROSS 2.9)%. Limits of detection (LOD) for aqueous standards varied from 0.67 (for sulphanilic acid) -0.03 pg mL-' (diaveridine).The linear dynamic range extended from the LOD for each drug to >5 pg mL-' .

Densitometric and Ratio Spectra Methods for Simultaneous Determination of Sulfaquinoxaline Sodium and Pyrimethamine in Binary Mixture

“…Also, capillary electrophoresis [30][31][32] was revealed for sulfaquinoxaline-Na determination. It was noticed that the only analytical methods have been described in the literature for the simultaneous determination of sulfaquinoxaline-Na and pyrimethamine in mixture were the first derivative of the ratio spectra [33,34] and HPLC [35][36][37] .…”

Spectrophotometric Determination of Sulfacetamide and Sulfamethaxazole in Aqueous Solution Using Tetracyanoethylene Reagent

“…Various methods have been reported for the determination of sulphonamides. These include gravimetric [4][5], titrimetric [6], potentiometric [7], amperometric [8] polarographic [9], chromatographic [10][11], flame spectroscopic [12], and fluorimetric [13], methods. Several spectrophotometric methods using various reagents such as 2,3-dichloro-5,6-dicyano-1,4-benzoquinone [14], 7,7,8,8 tetracyano quinodimethane [15], chloranil [16], 8-hydroxyquinoline [17], acetyl acetone-formaldehyde [18], furfuraldehyde [19], and N-(1-naphthyl) ethylene diamine [20], have been reported for determination of sulphonamide derivatives.…”