Chromatographic methods, robustness

Destandau, E., Vial, J., Jardy, A., Hennion, M.-C., Bonnet, D., and Lancelin, P. (2006). Robustness study of a reversed-phase liquid chromatographic method for the analysis of carboxylic acids in industrial reaction mixtures. Anal. Chim. Acta 572, 102—112. 

Sections above discuss typical chromatographic methods applied to TA samples. Beside sufficient separation, sensitive and selective detection is also required for robust and reliable analysis. The following section is addressed to different ionization interfaces, mass analysers and scan modes allowing valuable LC-MS method design. 

THE FACTORS AND THEIR LEVELS. EXAMINED IN THE ROBUSTNESS TEST OF (82) ON A CHROMATOGRAPHIC METHOD FOR THE SEPARATION AND ASSAY OF A DRUG SUBSTANCE AND TWO RELATED COMPOUNDS IN TABLETS... 

Chen R, Sekulic S, Zelesky T. Development and validation of a cost-effective, efficient, and robust liquid chromatographic method for the simultaneous determination of the acetyl and succinoyl content in hydroxypropyl methylcellulose acetate succinate polymer. J AOAC Int 2002 85(4) 824-831. Correction 85(6), 125A. Onda Y, Muto H, Maruyama K. Ether-ester derivatives of cellulose and their applications. United States Patent No. 4,226,981 1980. Final report on the safety assessment of hydroxyethylcellulose, methylcellulose, hydroxypropyl methylcellulose and cellulose gum. J Am Coll Toxicol 1986 5 1-59. 

Miscellaneous detectors. TLC, as with other chromatographic methods, is a separation not an identification technique and thus for unambiguous identification of analytes the separated components must be examined by spectroanalytical techniques. Mass [67] and Fourier-transform infrared spectrometry [68] have both been used to good effect and considerable effort is currently being expended to develop robust methodologies and instrumentation in these areas. Instrumentation has recently been developed, for example, which elutes separated components directly onto a measured amount of potassium bromide which is then automatically pressed and introduced into an infrared spectrometer. 

Maniara etal. [197] made a systematic exploration of experimental precision, accuracy, specificity, linearity, DL, QL, and robusmess, for NMR assays of agricultural chemicals. They concluded that carefully implemented QNMR can compete effectively widi chromatographic methods. The level of the major chemical ingredient can be determined with accuracy and precision significantly better than 1%. Impurities at the 0.1% or lower may also be quantified . For the robustness study, these workers chose the number of scans and the relaxation delay, then operator to operator and instrument to instrument variabihties were tested. Unlike Bauer etal., they found that purity values were Not significantly dependent on analyst or instrument , but perhaps this was because the work was performed in one laboratory, rather than several disparate laboratories, each of which may have their own way of working. The work of Maniara etal. therefore tested intermediate precision, whereas that of Bauer etal. tested reproducibility. 

The introduction of high-resolution, robust, rapid, selective, sensitive, precise, and accurate chromatographic methods is essential in food science, as well as in many other research fields, as illustrated in previous chapters of this book. The development and validation of methods to be employed in food analysis must be carried out with the greatest attention, following official protocols and guidelines (e.g., the U.S. Food and Drug Administration). The obvious reason is that foods are introduced into the human body and are, for the main part, absorbed. 

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