A method for the low-level (ng/g) determination of perfluorooctanoate in carpet by LC-MS-MS using matrix extracted standards.

Fluorotelomer-based acrylic polymers are applied to the surface of carpet to impart oil, stain, and water repellence properties. Concerns that fluorotelomer-based polymers are a possible source of "low level" exposure to humans, coupled with their widespread use have prompted the need to develop a method to detect and measure perfluorooctanoate (PFO) in carpet. A liquid chromatography tandem mass spectrometry method for the determination of PFO in carpet using a dual labeled 13C-perfluoroctanoic acid (13C-PFOA) internal standard is successfully developed and validated.

A method for the low-level (ng g(-1)) determination of perfluorooctanoate in paper and textile by liquid chromatography with tandem mass spectrometry.

The determination of perfluorooctanoate (PFO) in articles of commerce has become increasingly important to understand if treated products are a possible source of PFO. An LC-MS/MS method for the determination of PFO in paper and textile using a dual labeled 13C-PFOA internal standard was successfully developed and validated. Residues of PFO were determined using an isocratic, reversed-phase high-performance liquid chromatography (HPLC) method with an ammonium acetate/methanol buffer.

Iridoid glycoside metabolism and sequestration byPoladryas minuta (Lepidoptera: Nymphalidae) feeding onPenstemon virgatus (Scrophulariaceae).

A bivoltine checkerspot butterfly,Poladryas minuta, is aPenstemon specialist, not known to utilize any other plant genus for oviposition and larval feeding. At several intermontane plains sites of central Colorado, the butterfly utilizesPenstemon virgatus as its sole host plant. Analysis of the host plant showed it to contain three cinnamyl-type catalpol esters (scutellarioside-II, globularin, globularicisin) and catalpol.

Iridoid glycoside content ofEuphydryas anicia (Lepidoptera: Nymphalidae) and its major hostplant,Besseya plantaginea (Scrophulariaceae), at a high plains colorado site.

The checkerspot butterfly,Euphydryas anicia, utilizes mainlyBesseya plantaginea and only occasionallyCastilleja integra as a larval hostplant at Michigan Hill, a few kilometers from a site whereC. integra is used by over 90% of the butterflies. TheB.

Ultrastructural effects of Guillain-Barré serum in cultures containing only rat Schwann cells and dorsal root ganglion neurons.

Serum from patients with the acute form of the Guillain-Barré syndrome was applied to cultures containing only rat dorsal root ganglion neurons and Schwann cells. Serum taken from 4 of 10 patients during the first 1-3 weeks of clinical onset had previously been shown to have significant demyelinating activity in this culture system when observed at the light microscopic level. More detailed assessment made at the ultrastructural level showed that: (1) wide-spread myelin-related Schwann cell lysis occurred in concert with vesicular myelin breakdown; (2) non-myelin-related Schwann cells avidly phagocytized necrotic cell debris and fragments of compact myelin; and (3) neurites and non-myelin-related Schwann cells remained structurally undamaged.