Quantitation of radiolabeled biological molecules separated by high-performance liquid chromatography

General Methods for the Extraction, Purification, and Measurement of Steroids by Chromatography and Mass Spectrometry

“…Flow-through radioactivity detectors are potentially useful for examining the products of reactions with labelled substrates (Kessler, 1983;Lundmo and Sunde, 1984). The short dwell time of the sample components in the counting chamber limits sensitivity.…”

Radioactivity Detectors for High-Performance Liquid Chromatography in Drug Metabolism Studies

“…[46] In the following years further comparison of both off-line and on-line counting were performed and further optimizations in on-line detection were introduced to increase counting efficiency and peak resolution. [47][48][49][50][51][52] Due to the favorable properties of HPLC and on-line radioactivity detection, this combination developed into a routinely applied method for the investigation of metabolic profiles. [5,[53][54][55][56][57][58][59][60] The configuration of an on-line radioactivity detector in HPLC is similar to that of standard scintillation counters with the exception that the vial is replaced by a coiled tube positioned between two PMTs.…”

“…[65,66] Several publications dealt with a direct comparison of on-line heterogeneous and homogeneous scintillation counting. These comparisons showed that each mode has its own advantages and disadvantages, [49,50,52,60,67] as summarized in Table 1. Heterogeneous counting has favorable aspects with regard to consumable costs, sample recovery and safety whereas homogeneous counting still seems to be superior with regard to sensitivity and counting efficiency.…”

Other Modes of Detection

“…Kessler [12,13,14] compared on-line detection with fraction collection of steroid metabolites. He found the mean ratio of DPM on-line/DPM fraction collection was 0.784, demonstrating that fraction collection is more sensitive.…”

“…If sample recovery is of importance, an electronic stream splitter can be used as was employed by Kessler [12,13,14] and Roberts et al [10]. The first problem caused by scintillation fluid is that the fluid is not easily removed, therefore the sample is destroyed.…”