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Fluorigenic labelling techniques have been used for several years in conjunction with thin-layer chromatography, and are now being used also to good advantage in high-speed liquid chromatography. In this work, reagents such as 4-chloro-7-nitrobenzo-2,1,3-oxadiazole, dansyl chloride and dansyl-hydrazine were used for the fluorigenic labelling of carbamates, ureas, organophosphorous compounds, aliphatic amines, aldehydes, ketones, biphenyls and some compounds of pharmaceutical interest. The labelling reactions and the nature of derivatives are discussed, together with the column liquid chromatography properties of these derivatives in both liquid—liquid and solid—liquid modes. Detection limits obtained for most compounds with a new fluorimetric detection device range between 1 and 10 ng per 4-μl injection volume. The method is suitable for quantitative analysis, with a reproducibility of ca. 3% relative standard deviation. Linear calibration plots for peak area or peak height versus concentration were observed up to 600 ng per injection. The method has been applied successfully to the environmental sample analysis of pesticides in water, soil and vegetables without the necessity for a preliminary clean-up. The method is comparable in sensitivity and accuracy to gas chromatography. The advantages of this method can be summarized as follows: improved detection properties, such as better sensitivity, flow-insensitive detection mode and higher specificity; lowering of polarity of the compounds, hence greater ease of separation; suitable for automation and routine analysis; the range of possible applications is limited only by the available labelling reagents and separation procedures.

Three methods are described which allow the quantitative analysis of hydrogen in gaseous mixtures, when helium is the carrier gas. These methods are respectively based on the simultaneous calibration with air, the simultaneous calibration with hydrogen and the determination of the correction factor curve. All the methods can be applied to other carrier gases and samples.

The support phase has been shown to influence values for relative retention by either the adsorption of solute moleculs or the adsorption of the hydroxyl groups of certain polar liquid phases. Also, it has been deduced that appropriately shaped molecules, which have a low affinity for the solvent, can be selectively retained by trapping in the micro pores in the surface of certain supports, in particular teflon. On the basis of these observations it has been found that silanized Chromosorb G is the least adsorptive of a wide range of commercially available support materials.

The ideal detector for quantitative analysis by gas chromatography would need neither calibration nor the application of integration procedures to a differential chromatogram. This paper describes the experimental realization of a detector possessing these two desirable characteristics. The “Brunel” mass integral detector yields an integral chromatogram in which the absolute masses of the sample components are directly recorded as step-heights.

Nine European laboratories have taken part in a joint exercise in which two samples, one containing about 98% benzene and the other 90% toluene, were analysed, using chromatographic equipment available to each laboratory. For each sample, a known quantity of a specified internal standard was used and the composition of the samples was calculated from calibration data based on (I) peak height, (2) peak height X retention distance, (3) peak height x width of peak at half peak height. The precision of the results is least for method (3), but method (I) is preferred because it is the simpliest. The results for the toluene sample were less precise than those for the benzene sample. Further work is in progress.

The flame-ionisation detector has a linear reponse over a range of four orders of concentration, i.e. 10 −0 to 10 −10 g/ml, and this range could probably be extended to six orders by employing suitable experimental conditions. The detector response is independent of the applied voltage, over the range of 25—150 V, and has a sensitivity of approximately 10 −11 g/ml. The macro-argon ionisation detector has a linear response over a small concentration range at one particular voltage, the value of which may vary from one substances to another. Inclusion of a linearising resistance does not result in a linear response. Calibration of the macro-argon detector is essential for accurate quantitative analysis due to the variability of the response index. The sensitivity of the detector is about 10 −13 g/ml.