Determination of Ephedrine Alkaloids in Dietary Supplements and Botanicals by Liquid Chromatography/Tandem Mass Spectrometry: Collaborative Study

An interlaboratory study was conducted to evaluate the accuracy and precision of a method for ephedrine-type alkaloids [i.e., norephedrine (NE), norpseudoephedrine (NPE), ephedrine (E), pseudoephedrine (PE), methylephedrine (ME), and methylpseudoephedrine (MPE)] in dietary supplements and botanicals. The amount of ephedrine-type alkaloids present was determined using liquid chromatography with tandem mass selective detection. The samples were diluted to reflect a concentration of 0.0200 to 1.00 μg/mL for each alkaloid. An internal standard was added and the alkaloids were separated using a 5 μm phenyl LC column with an ammonium acetate, glacial acetic acid, acetonitrile, and water mobile phase. Eight blind duplicates of dietary supplements or botanicals were analyzed by 10 collaborators. Included was a negative control, ephedra nevadensis, and negative controls fortified at 2 different levels with each of the 6 ephedrine-type alkaloids. The spike levels were approximately 100 and 1000 μg/g for NE, 100 and 600 μg/g for NPE, 6500 and 65 000 μg/g for E, 1000 and 10 000 μg/g for PE, 300 and 3000 μg/g for ME, and 100 and 1000 μg/g for MPE. On the basis of the accuracy and precision results for this interlaboratory study, it is recommended that this method be adopted Official First Action for the determination of 6 different individual ephedrine-type alkaloids in dietary supplements and botanicals.

Root apex structure in Ephedra nevadensis

The distinctive, large cells in the central region of the root apex of Ephedra nevadensis Wats. which do not incorporate [3H]thymidine and stain lightly with Feulgen reagent comprise the quiescent centre. These cells and adjacent meristem cells remain at the 2C–4C level of DNA. Ultrastructurally, cells of the quiescent centre are characterized by possessing proplastids, numerous ribosomes, small vacuoles, and few plasmodesmata. The root cap consists of a columella and periphery. Nuclei of columella cells are either at the 2C or 4C level of DNA as determined by microspectrophotometry. The mitotic index remains high up to 50 cell tiers from the quiescent centre – root cap boundary. Starch deposition is delayed considerably in columella cells but not in peripheral cells. The root cap of this genus is unique in its method of growth.

Shasta ground sloth food habits, Rampart Cave, Arizona

The feces of the Shasta ground sloth (Nothrotheriops shastense), preserved by the arid climate of the lower Grand Canyon, were collected at various levels and examined by microhistological analyses to identify and quantify plant taxa in the diet. Over 500 pieces of different Shasta sloth coprolites were examined. Sloth dung from the nearby Muav Caves was examined and compared with that from Rampart Cave.Seventy-two genera of plants were identified in the sloth dung deposited discontinuously from over 40,000 to about 11,000 yr BP. The major plant taxa in the Rampart Cave sloth diets were desert globemallow (Sphaeralcea ambigua = 52%), Nevada mormontea (Ephedra nevadensis = 18%), saltbushes (Atriplex spp. = 7%), catclaw acacia (Acacia greggii = 6%), Cactaceae spp. (= 3%), common reed (Phragmites communis = 5%), and yucca (Yucca spp. = 2%).Six of the most abundant plants in sloth diets were collected in the environs of Rampart Cave and were analyzed for their energy, fiber and nutrient values. The simulated diets of Rampart Cave sloths averaged 1679 cal/g in digestible gross energy and 7.9% for digestible protein. Apart from a substantial increase in digestible energy and in mormontea there was no unusual change in the sloth diet immediately prior to the time of their extinction.The ecological role of Nothrotheriops shastense is less dramatically different from that of extant desert herbivores than was previously believed.