Direct solid-phase isolation and oximation of prostaglandin E2 from plasma and quantitation by gas chromatography with mass spectrometric detection in the negative-ion chemical ionization mode

Abstract

A solld support of potystyrene-dlvlnylbenzene cross-linked copolymerlc macroretlcular resln was used to simultaneously adsorb and oxlmate a carbonyl-contalnlng prostaglandln directly from plasma. The process was carrled out at room temperature and was complete M M n 20 mln. Thts technlqua slmpllfled one of the exactlng analytlcal derlvatlzatlons of current methods and substantlalty reduced the time required In sample preparatlon of thls analyte for gas chromatography/mass spectrometry wlth negatlvelon chemlcal Ionlzatbn detecth. The Inveetlgath Mentlfled oxhatlng reagents that produced derlvatlves wlth deslred negatlve-Ion chemical-lonlzatlon-lnduced fragmentatlon. The pH of the aqueous phase In the reactlon mlxture, the physlcal characterlstlcs of these reagents, and aqueous-based derlvatlzatlon of carbonyls on a llpophlllc sterold lndlcated that the site of the reaction was the resln surface.

Bisphenol A (BPA) daily intakes in the United States: Estimates from the 2003–2004 NHANES urinary BPA data

“…To achieve enhanced sensitivity and selectivity, the phenols have been derivatized to alkyl or acyl derivatives before GC-mass spectrometry (GC/MS) analysis. [23][24][25][26][27][28][29][30][31] We have developed a sensitive method for measuring BPA, 4-tert-octylphenol (tOP), benzophenone-3 (BP-3), and five chlorophenols [2,4-dichlorophenol(24-DCP), 2,5-dichlorophenol (25-DCP), 2,45,-trichlorophenol (245-TCP), 2,4,6-trichlorophenol (246-TCP) and triclosan]. The method uses solid phase extraction (SPE) coupled on-line to HPLC and tandem mass spectrometry (MS/MS).…”

Sample Preparation Techniques for Mass Spectrometry in Proteomics Using Recently Developed Highly Selective Materials

“…It is also similar to liquid-solid extraction (LSE), where the extraction procedure consists in putting the analytes into a vessel with a suitable adsorbent material (solid phase) and shaking for a fixed time (Scheepers et al, 1993;Rosenfeld et al, 1991). The analytes to be extracted are partitioned between a solid and a liquid -rather than between two immiscible liquids as in LLE -and these analytes must have a greater affinity for the solid phase than for the sample matrix (retention or adsorption step).…”

Métodos de extração e/ou concentração de compostos encontrados em fluidos biológicos para posterior determinação cromatográfica

“…As fases de imunoafinidade, onde um anticorpo específico é imobilizado em um suporte sólido, tal como agarose ou sílica, também têm sido utilizadas em análises de amostras de importância biológica. Um exemplo é a determinação de insulina em amostras de plasma, onde a extração seletiva é realizada em uma coluna recheada com o seu anticorpo anti-insulina (nome original AE9D6) 45 . Os MIP são obtidos através da preparação de polímeros com sítios de reconhecimento sintéticos e têm uma seletividade pré-determinada para um ou mais analitos [46][47][48][49][50] .…”