Dersleri yüzünden oldukça stresli bir ruh haline sikiş hikayeleri bürünüp özel matematik dersinden önce rahatlayabilmek için amatör pornolar kendisini yatak odasına kapatan genç adam telefonundan porno resimleri açtığı porno filmini keyifle seyir ederek yatağını mobil porno okşar ruh dinlendirici olduğunu iddia ettikleri özel sex resim bir masaj salonunda çalışan genç masör hem sağlık hem de huzur sikiş için gelip masaj yaptıracak olan kadını gördüğünde porn nutku tutulur tüm gün boyu seksi lezbiyenleri sikiş dikizleyerek onları en savunmasız anlarında fotoğraflayan azılı erkek lavaboya geçerek fotoğraflara bakıp koca yarağını keyifle okşamaya başlar

GET THE APP

Identification and Reduction of Matrix Effects Caused by Cremophor EL in Bioanalysis Using Liquid Chromatography/Tandem Mass Spectrometry | OMICS International | Abstract
ISSN: 2155-9872

Journal of Analytical & Bioanalytical Techniques
Open Access

Our Group organises 3000+ Global Conferenceseries Events every year across USA, Europe & Asia with support from 1000 more scientific Societies and Publishes 700+ Open Access Journals which contains over 50000 eminent personalities, reputed scientists as editorial board members.

Open Access Journals gaining more Readers and Citations
700 Journals and 15,000,000 Readers Each Journal is getting 25,000+ Readers

This Readership is 10 times more when compared to other Subscription Journals (Source: Google Analytics)

Research Article

Identification and Reduction of Matrix Effects Caused by Cremophor EL in Bioanalysis Using Liquid Chromatography/Tandem Mass Spectrometry

Vijaya Bhaskar V1 *, Anil Middha2 , Sudhir Tiwari1 and Savithiri Shivakumar1

1DMPK Laboratory (Biology Division), GVK BIO, Hyderabad, India

2Department of Pharmacy, Jagadishprasad Jhabermal Tibrewala University, Rajasthan, India

*Corresponding Author:
Vijaya Bhaskar V
DMPK Laboratory (Biology Division)
GVK BIO, Nacharam, Hyderabad
Andhra Pradesh, India-500076
Tel: +918143853440
E-mail: veeravalli.bhaskar@gmail.com

Received date: March 05, 2013; Accepted date: June 11, 2013; Published date: June 13, 2013

Citation: Vijaya Bhaskar V, Middha A, Tiwari S, Shivakumar S (2013) Identification and Reduction of Matrix Effects Caused by Cremophor EL in Bioanalysis Using Liquid Chromatography/Tandem Mass Spectrometry. J Anal Bioanal Tech 4:167. doi: 10.4172/2155-9872.1000167

Copyright: © 2013 Vijaya Bhaskar V, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Ion suppression effect of dosing vehicle excipient Cremophor EL (CrEL) on the accuracy of liquid chromatography/ tandem mass spectrometry (LC-MS/MS) measurements was studied. Ion suppression cause significant errors in accuracy of the measured concentrations of test compounds, thereby invalidating the assessment of pharmacokinetic results. Using CrEL as a probe compound, the concentration-time profile of the excipient in plasma from rats dosed both orally and intravenously was determined. The most abundant molecular ions corresponding to PEG oligomers at m/z 828, 872, 916 and 960 with daughter ion at m/z 89 were selected for multiple reaction monitoring (MRM) in electrospray mode of ionization. Plasma concentrations of CrEL ranging from 0.50-1.0 mg/mL in the initial sampling points caused 2-10 fold ion suppression on most of the analytes studied. This can result in false rejection of compounds in a drug discovery screen. In this paper, various sample preparation methods, enhanced chromatographic selectivity, and alternative ionization methods were investigated as means to avoid or minimize ion suppression effects. The elimination of ion suppression effects was achieved by Liquid-Liquid Extraction (LLE) with hexane, TBME in Electrospray Ionisation (ESI) mode as sample preparation method. In contrast to ESI mode that had severe suppression effects from CrEL, atmospheric pressure chemical ionisation (APCI) mode is totally free of suppression effects. The mechanism of ion suppression caused by CrEL in relation to both liquid and gas phase reactions was discussed.

Keywords

Top