JOSHUA E. YOUNG

MicroSolv Technology Corporation, 9158 Industrial Boulevard N.E., Leland, NC 28451, USA

Abstract

A brief overview of the applicability of silica hydride HPLC columns to some of the more challenging issues faced by analysts of the food and beverage industry is presented. In particular, the problem of adequately retaining polar compounds present in foodstuffs is discussed. Examples are given for various pertinent areas: water-soluble vitamins, toxic or undesirable compounds, and sugars. Reversed phase applications featuring more hydrophobic molecules are also discussed, highlighting issues in sample preparation and removal of matrix components. In each instance, the chromatographic obstacles are explained, as well as how silica hydride materials are able to address them.

INTRODUCTION

While traditional reversed phase chromatography remains the workhorse method for many routine HPLC food and beverage applications, it is generally unsuitable for the analysis of polar compounds due to poor chromatographic retention of the analytes. In fact, a good number of compounds in foodstuffs are polar in nature, including hydrophilic vitamins, sugars, and even certain adulterants. In this latter case, one high profile example in recent years was the introduction of melamine to milk products in China, reportedly as a deliberate and insidious attempt to skew their protein content assays based on total nitrogen content. When combined with cyanuric acid, melamine forms melamine cyanurate crystals, which have been implicated in life-threatening renal failure. Hence, there was an exigent need for detection of both melamine and cyanuric acid in foodstuffs to ensure safety to the consumer. The problem, however, was that both compounds are highly polar and not easily retained and separated by conventional HPLC methods.
Examples like this illustrate the need for chromatographic stationary phase technology to catch up with the growing ...