The Column - March 2008 - (Page S7)

2D-HPLC FOR BIOANALYSIS “CO-SENSE FOR BA” SYSTEM The Co-Sense for BA system features the unique “Shim-pack MAYI Series” of pretreatment columns and enables automated sample pretreatment for better reproducibility of bio-sample analysis. C/MS with high sensitivity and selectivity is a powerful tool for pharmacokinetic, clinical and metabolic studies. Biological samples such as plasma, serum and urine are pretreated to minimize the influence by proteins and matrices in the sample before injection into LC/MS. Recently, several restricted access media (RAM) columns have been developed to enable on-line pretreatment of biological samples. Internal surface reversed-phase columns1-4, mixed functional phase silica5, semi-permeable surface silica6, and diol silica7,8 have been reported as approaches to enable automated sample pretreatment. A methyl cellulose-immobilized reversed-phase column MC-ODS (Shim-pack MAYI-ODS) was prepared by modification of porous silica with methyl cellulose, followed by modification of the internal surface with ODS9. The external surface covered with L methyl cellulose prevents adsorption with proteins while small molecules can be retained in the internal surface by hydrophobic interaction with the ODS groups. Shim-pack MAYI-ODS columns enable direct injection of biosamples, such as plasma, by using a column-switching technique9,10. In the reversed-phase RAM column, polar compounds have weak retentive properties, since the retention is due to hydrophobic interactions, and the recovery rate of polar compounds is reduced. MC-SCX (Shim-pack MAYISCX)11,12 and Shim-pack MAYI-SAX have ion-exchange groups inside the pores and can be successfully applied to the analysis of hydrophilic compounds in plasma. We have discussed the principle and potential applications of the Co-Sense for BA system, which is configured from a column-switching system and a MAYI pretreatment column, in previous LC World Talk issues and application notes. Here, we summarize the features and applications of Co-Sense for BA. Shim-pack MAYI Series Shim-pack MAYI series columns are on-line pretreatment columns for HPLC which are designed to extract and concentrate analytes in bio-samples. The packing material is composed of totally porous, high-purity spherical silica particles. The outer surfaces of the silica particles are coated with methyl cellulose polymer, and the inner surface of the pores are chemically bonded with stationary phase such as C18. The MAYI series has a wide variety of stationary phase, and the chemistries of the MAYI series are listed in Table 1. Winter 2008 www.shimadzu.eu Winter 2008 www.shimadzu.eu 7 http://www.shimadzu.eu

Table of Contents for the Digital Edition of The Column - March 2008

The Column - March 2008
Contents
News
Zosimus - Never Mind the Selectivity - Look at the Plate Count!
HPLC Analysis of Lysozyme in Different Types of Wine
Market Trends & Analysis
A Holistic Approach to Increasing Analytical Throughput on a Modern Gas Chromatograph
If It's Broke, Fix It - Q&A
The Applications Book
LC World Talk - Shimadzu's Newsletter for the HPLC Global Community
LC World Talk Contents
Applications of Ultra Fast HPLC
The World's Most Advanced Liquid Chromatograph
2D-HPLC for Bioanalysis "Co-Sense for BA" System
Metabolite Identification Software

The Column - March 2008