High performance liquid chromatography precision

Bowers, L.D. Cyclosporine analysis by high-performance liquid chromatography precision, accuracy, and minimum detectable quantity. Transplant.Proc., 1990, 22, 1150-1154 Gupta, S.K. Benet, L.Z. HPLC measurement of cyclosporine in blood plasma and urine and simultaneous measurement of its four metabolites in blood. J.Liq.Chromatogr., 1989, 12, 1451-1462 [cyclosporine A plasma urine simultaneous metabolites LOD 30 ng/mL cyclosporine D (IS) column temp 70]... 

As a consequence of the previous considerations Kieber et al. [75] have developed an enzymic method to quantify formic acid in non-saline water samples at sub-micromolar concentrations. The method is based on the oxidation of formate by formate dehydrogenase with corresponding reduction of /3-nicotinamide adenine dinucleotide (j6-NAD+) to reduced -NAD+(/3-NADH) jS-NADH is quantified by reversed-phase high performance liquid chromatography with fluorimetric detection. An important feature of this method is that the enzymic reaction occurs directly in aqueous media, even seawater, and does not require sample pre-treatment other than simple filtration. The reaction proceeds at room temperature at a slightly alkaline pH (7.5-8.5), and is specific for formate with a detection limit of 0.5 im (SIN = 4) for a 200 xl injection. The precision of the method was 4.6% relative standard deviation (n = 6) for a 0.6 xM standard addition of formate to Sargasso seawater. Average re-... 

High-performance liquid chromatography is also called high-precision and high-pressure liquid chromatography. 

The isocratic system (Fig. 1.2 (a)) provides an economic first step into high-performance liquid chromatography techniques. The system is built around a high-performance, dual-piston, pulse-free pump providing precision flow from 0.01 to 5ml min-1. 

Lanina et al. 1992 Oishi 1990). These methods include gas chromatography (GC) combined with mass spectrometry (MS) and high-performance liquid chromatography (HPLC) combined with an ultraviolet detector (UV). No comparisons can be made between methods since no data were given regarding sensitivity, recovery, or precision. 

High-performance liquid chromatography (HPLC), followed by GC/MS, has been used to fractionate and then quantitate the aliphatic and aromatic hydrocarbons present in liquid fuel precursors in order to determine the fuel potential of the compounds. Kerosene had the advantage of not requiring any sample preparation. Other light fuel oils may require the use of methylene chloride as a solvent prior to HPLC analysis (Lamey et al. 1991). The sensitivity, precision, and recovery of this method were not reported. 

When seeking a tool which could be used to determine the biological activity of mixture components in a more precise way, researchers directed their attention towards high-performance liquid chromatography (HPLC). Its advantage over TLC is its higher resolution, which helps to avoid false results caused by the co-elution of different compounds. 

A method for the determination of personal exposure to benzidine-based dyes has been developed. This procedure involved the reduction of benzidine-based dye filter samples to free benzidine with neutral buffered sodium hydrosulfite solution. The benzidine-containing reduction solution was then analyzed by high performance liquid chromatography. The reduction was found to be quantitative by visible-spectrum analysis. This reduction and analysis method was evaluated with four benzidine-based dyes over the range from 12 to 300 micrograms per sample. Precision for the reduction and analysis of the four dyes falls within % coefficient of variation. This method can differentiate between benzidine-and benzidine congener-based dyes. Results are reported in terms of free benzidine. 

MG Scanlon, HD Sapirstein, W Bushuk. Evaluation of the precision of high-performance liquid chromatography for wheat cultivar identification. Cereal Chem 66 112-116, 1989. 

High-performance liquid chromatography (HPLC) is a fast technique that, with high precision and specificity, separates mixtures into individual ingredients. Used as a routine procedure, it has several advantages It can be completely automated sample cleanup and preparation are simple and the reproducibility of the packing material means that the analytical conditions remain the same for a new column. 

Herniman, J. M., Bristow, T. W. T., O Connor, G., Jarvis, J., and Langley, G. J. (2004). Improved precision and accuracy for high-performance liquid chromatography/Fourier transform ion cyclotron resonance mass spectrometric exact mass measurement of small molecules from the simultaneous and controlled introduction of internal calibrants via a second electrospray nebuliser. Rapid Commun. Mass Spectrom. 18 3035-3040. 

Compared to other bioanalytical methods such as high-performance liquid chromatography (HPLC), the methods used to quantitate mAbs often display less precision and a higher between-day variability. In choosing a bioanalytical method it must also be considered that some assays measure the unbound fraction, the bound fraction, or both. When using FACS, only the fraction of the therapeutic antibody that is bound to its antigen on the cells is counted. In contrast, ELISA measures only the unbound fraction in serum that can react with the offered antigen. 

ASTM-Task Group E1908, An evaluation of quantitative precision in high-performance liquid chromatography, J. Chromatogr. Sci., 19 338 (1981). 

Kerr el. al. [307] employed high performance liquid chromatography for the determination of uranium in groundwaters. The sample was passed through a small reversed phase enrichment cartridge, to separate the uranium from the bulk of the dissolved constituents. The uranium was then back flushed from the cartridge onto a reversed phase analytical column. The separated species were monitored spectrophotometrically after reaction with arsenazo(III). The detection limit was in the 1-2gg L 1 range with a precision of approximately 4%. 

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