LCGC Asia Pacific-03-01-2014
Myths in Ultrahigh-Pressure Liquid Chromatography
March 1st 2014The advent of ultrahigh-pressure liquid chromatography (UHPLC) and its successful commercialization in the last few years has brought forth a modern high performance liquid chromatography (HPLC) platform capable of higher speed, resolution, precision, and sensitivity. Currently, all major HPLC manufacturers have some type of low-dispersion UHPLC products with upper pressure limits ranging from 15,000 to 19,000 psi (1000 to 1300 bar) on the market. This installment describes a number of popular myths or half-truths in UHPLC and provides data that contradict or even repudiate some of these commonly held beliefs.
Strategies for the Detection and Elimination of Matrix Effects in Quantitative LC–MS Analysis
March 1st 2014Currently available methods for the detection of matrix effects in liquid chromatography–mass spectrometry (LC–MS) are tedious and complex; therefore, a simpler method is required. Although there are no methods to completely eliminate matrix effects, the most well-recognized technique available to correct for matrix effects is that of internal standardization using stable isotope–labelled versions of the analytes. As this method can prove expensive, an alternative method of correction is likely to be useful. In this study, a simple method based on recovery is assessed for the detection of matrix effects. Two alternative methods for the rectification of matrix effects in LC–MS are also assessed: Standard addition and the coeluting internal standard method.
