Rapid Quantitative Determination of Three Active Ingredients in Liquid Antitussive Preparations by High-Speed Liquid Chromatography

The Quantitative Determination of Dextromethorphan Hydrobromide in Cough Remedies by High Precision Liquid Chromatography (Hplc)

“…Menyharth et al (2) determined dextromethorphan in liquid antitussive preparations by High Pressure Liquid Chromatography (HPLC) . Menyharth et al (2) determined dextromethorphan in liquid antitussive preparations by High Pressure Liquid Chromatography (HPLC) .…”

Potential error in single-point-ratio calculations based on linear calibration curves with a significant intercept

“…In cases where the SPRC technique is used, and an author either makes only a simple linearity statement, or discloses by a response curve or by regression analysis data that an intercept value was observed, the reader cannot make any conclusion as to whether or not this potential error source was simply ignored as negligible or was unrecognized (15,17,18,(22)(23)(24). It is only fair to point out, however, as this paper will show, that in either case, under certain fortuitous circumstances involving the sample and standard responses, no computational error in the result may, in fact, exist.…”

“…It is only fair to point out, however, as this paper will show, that in either case, under certain fortuitous circumstances involving the sample and standard responses, no computational error in the result may, in fact, exist. Intercepts in response curves are often encountered with positive or negative values almost always of the algebraic sign as predictable from the type of measured signal: positivefluorometry (3,20), spectrophotometry (22,23), spectrofluorodensitometry or spectrophotodensitometry (3,7,25); negative-polarography (4), GLC (19), HPLC (6,24). It is the purpose of this paper to evaluate both qualitatively and quantitatively the bias error caused by an SPEC calculation from an assumed linear response curve through zero for the case where the true response curve is a straight line with a significant intercept.…”

Liquid chromatographic analysis of pharmaceutical syrups using pre-columns and salt-adsorption on Amberlite XAD-2

“…The liquid chromatographic behavior of a number of drugs on nonpolar bonded phases has also been reported (5,6) but syrup samples with their multitude of potentially interfering "inert" ingredients were not analyzed and amine drugs showed considerable tailing (5). Chromatography of syrup samples on a nonpolar bonded phase (octadecylsilyl) required preliminary liquid-liquid extraction (7) to eliminate interferents. When chromatographing amines on nonpolar bonded phases, the pH was adjusted to a value at which the nonionized free-base was the adsorbed species (5)(6)(7)(8).…”