Automated analysis of antiepileptic drugs in serum by column-switching high-performance liquid chromatography

Basic Concepts and the Control of Separation

“…The use of boxcar chromatography has rarely been reported in the literature [83], and today the availability of mass spectrometric detection might seem to further reduce the potential advantage of this technique for most samples. Where extremely large values of N are required for resolution-as in the preparative separation of compounds differing only in isotopic substitution-boxcar chromatography offers the possibility of achieving a much higher throughput rate than by any other technique.…”

Sample Preparation for Chromatographic Analysis

“…In the multidimensional mode, two columns containing the same stationary phase but of different lengths or two columns of similar length but of different selectivity are used. Snyder has adapted this technique to a process he termed "boxcar chromatography" [299,300]. The components of low retention are switched to the second column (1) and remain there while the most retained components are separated on the first column (2) .…”

“…Trace enrichment and sample cleanup on short precolumns are finding increasing use in the automated determination of drugs in biological fluids by liquid chromatography [12,285,291,300,[312][313][314][315]. The main problem in injecting untreated plasma or serum samples, and to a lesser extent urine samples, onto reversed-phases columns is the incompatibility of the sample matrix with the column system.…”

Milk production and energy metabolism in ruminants fed 2-ketoisocaproate

“…Eluent was heated to 90' for 10 min to remove acetoacetate, and then organic acids thus-, very late eluting compounds (later than 25 min) eluted within the first 8 min (Nazareth et al, 1984). Acetate eluted at about 17 min, was detected by absorbance of UV light at 214 nm, and was collected for determination of radioactivity by scintillation counting.…”