A solid-phase extraction (SPE) cleanup and a liquid chromatographic (LC) method with UV detection is presented for analysis of up to 7 ephedrine alkaloids in herbal products. Alkaloids from herbal products are extracted with acidified buffer, isolated on a propylsulfonic acid SPE column, eluted with a high-ionic-strength buffer, and separated by LC with detection at 255 nm. LC separation is performed by isocratic elution on a YMC phenyl column with 0.1 M sodium acetate-acetic acid (pH = 4.8) containing triethyl-amine and 2% acetonitrile. Ephedrine alkaloids are completely separated in 15 min. Average recovery of 5 common alkaloids from 3 spiked matrixes is 90%, with an average relative standard deviation (RSD) of 4.4% for alkaloid spikes between 0.5 and 16 mg/g. Average quantitation of ephedrine and pseudoephedrine from 6 herbal products is 97% of declared label claims, and average quantitation of synephrine from an herbal dietary product is 85% of label claim (RSD, 3.2%). Recoveries of synephrine, norephedrine, ephedrine, pseudoephedrine, N-methylephedrine, and N-methylpseudoephedrine spiked in 4 herbal products averaged 95%. Results of ruggedness testing and of a second laboratory validation of the procedure are also presented.
A direct elevated temperature plate count method utilizing modified fecal coliform agar with rosolic acid (ETPC/mFC) was compared to 5-tube and 3-tube most probable number (MPN) procedures for its accuracy in enumerating fecal coliforms and Escherichia coli in naturally and artificially contaminated soft-shell clams (Mya arenaria). The results indicated that the extent of overall recovery of fecal coliforms was similar in the two methods tested. Therefore, the ETPC/mFC method may be considered as a rapid procedure for fecal coliform screening during depuration of soft-shell clams.
Using antibodies raised against the purified i protein, the expression of the chromosomal uncl gone was demonstrated. The i protein was identified as a component of the cytoplasmic membrane and shown to be present in preparations of F,, or F~F,,. The protein is not associated with the F~ moiety.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.