Thirtieth anniversary of the retention index according to Kováts in gas-liquid chromatography

Retention indices in micellar electrokinetic chromatography

“…In gas chromatography (GC) retention indices have found widespread application for the identification of substances in complex matrices [4][5][6]. They are considered to express retention with the best reproducibility and precision.…”

Linear retention indices in gas chromatographic analysis: a review

“…The McReynolds values are used to evaluate the degree of similarity between stationary phases, to rank the phases by degree of polarity and to predict the elution order of the analytes. The Rohrschneider concept and related calculation methods represent a very important research area, 6,7,13 and both the aforementioned approaches are widely applied to characterize and classify stationary phases. However, the McReynolds system may often contain erroneously measured data; an additional drawback is that the constants are determined only at 120°C.…”

“…The prediction of programmed temperature retention indices is also an in-depth discussed subject, 12 involving the calculation and theoretical determination of the elution order of many compounds. Retention index systems have been exhaustively reviewed by Budahegyi et al 6 and Tarján et al 7 The present contribution provides an overview of the theoretical aspects and applications of retention indices to gas chromatographic analysis. It is certain that the references cited in this review represent a very small part of the studies performed on retention index theories and their applications.…”

“…However, when isothermal steps are included in the temperature programme or the rate is changed during the analysis, the calculation of the indices is more troublesome. [5][6][7] It is worthy of note that discrepancies may arise from the fact that the retention index values are reported by many different laboratories and the operating conditions are not always reliable. Moreover, it should be pointed out that differences may also arise from the use of columns coated with identical stationary phase but manufactured by distinct companies.…”

Preliminary study of the retention behavior for different compounds using cryogenic chromatography at different initial temperatures

“…Their I values are arbitrarily assigned to equal the carbon number atoms (n) in the molecule multiplied by 100 [9]. In these years, temperature dependence of the retention data, especially of Kováts indices, has been studied for a long time [10,11], although inconclusively to a large extent. In many cases, linear approximation provides excellent results within the commonly applied temperature ranges and for the nonpolar stationary phases [11,12].…”