Use of Ionic Dyes in Analysis of Ionic Surfactants and Other Ionic Organic Compounds

Revalidation and rationale for high pKa values of unconjugated bilirubin

“…Our chloroform was not only thus purified, but was also stored for less than 72 hr in the dark, in an argon atmosphere, under a layer of purified water, which stabilizes the CHCl 3 against regeneration of the oxidative products [17]. Water-stabilized CHCl 3 has been used successfully for quantitative analysis of anionic and cationic lipids in water at concentrations as low as 10 -6 M, by their nearly complete extraction as ion pairs with cationic and anionic dyes [13,19,20]. In those studies, no serious impurities were noted in the blank values, rendering it unlikely that significant lipid impurities were present in the similarly-prepared CHCl 3 that was utilized in our present and prior [3] partition studies with UCB.…”

Calculation of contact angles from surfactant adsorption isotherms

“…Sulfonate analysis: Aqueous methylene blue-sulfonate complex was extracted into chloroform and its optical density at 645 mlm was related to amount of sulfonate with a calibration curve [16].…”

Physical properties of bovine white matter proteolipid apoprotein–sodium dodecyl sulfate complexes

“…determined by the methylene blue extraction procedure of Mukerjee [18]. PLA concentration was determined by either the modified Lowry procedure of Lees and Paxman [19] with bovine serum albumin as a standard, or the protein Amidoschwarz dye complex method of Schaffner and Weissmann [20].…”