Analysis of polychlorinated naphthalenes by high-performance liquid and thin-layer chromatography

Gas chromatographic retention behaviour of polychlorinated naphthalenes on non-polar, polarizable, polar and smectic capillary columns

Six commercially available gas chromatography columns were investigated for performance in separating polychlorinated naphthalenes (PCNs). Retention behaviour on the investigated phases is compared and retention data for 40 congeners on a 5% phenyl-methylpolysiloxane column is reported. For all columns, except the octylmethylpolysiloxane and the smectic, a relation between substitution pattern and retention was found, where substitution in adjacent positions as well as alpha-substitution increase the retention time. A mathematical model based on these findings was developed and used to predict the relative retention of all congeners from di- up to octachloronaphthalene, on a 5% phenyl-methylpolysiloxane column.

Room temperature phosphorescence as a liquid chromatographic detection method for polychlorinated naphthalenes and biphenyls in complex matrices

Quenched and sensitized room temperature phosphorescence techniques have been used for the detection of PCNs and PCBs after liquid chromatographic separation. The usefulness of these techniques to fingerprinting of commercial Aroclor and Halowax mixtures in complex matrices has been shown. The complementary nature of these detection modes yield valuable information in addition to UV detection. a signal inverter is proposed for linearization of the quenched RTPL signals. In this way linear calibration plots over more than two orders can be obtained. Detection limits are generally in the low nanogram or subnanogram concentration region. The application of RTPL detection techniques to the analysis of commercial PCN and PCB mixtures in surface water and urine is demonstrated. Pre-columns can be used to advantage for pre-concentration and clean-up of this type of samples.

An evaluation of chromatographic methods for the analysis of polychlorinated terphenyls in environmental samples

Gas chromatography (GC) with packed and capillary columns, high-performance liquid chromatography (HPLC) and thin-layer chromatography have been used to characterize various commercially available mixtures of polychlorinated terphenyls (PCTs). Besides, UV absorption and mass spectrometry data have been collected, and the behaviour of PCTs upon perchlorination to the tetradecachloroterphenyls has been studied. Using GC, the PCT content of a number of paper and sewage sludge samples has been determined. The application of perchlorination/GC as method of analysis often yields unreliable, i.e., too high, results compared with the direct GC pattern-comparison method. In the case of paper samples, hydrogenated terphenyls appear to be the principal interfering compounds.

Separation of organophosphate, chlorinated, and carbamate insecticides using conventional and reverse-phase thin-layer chromatography

This paper demonstrates that the RPTLC system can be used as a confirmation tool for regular adsorption TLC because it separates the pesticides of interest and also reverses their positions on the plate due to their partitioning with water solubility. A clinical procedure was devised for screening samples of gastric and urine for chlorinated, organophosphate, and carbamate insecticides via the use of conventional TLC. The presence of these insecticides was then confirmed by reverse-phase TLC via spotted TLC plates. In view of the plethora of insecticides currently found in the home, and in view of the numerous incidents of adults and children accidentally or purposely ingesting them. This confirming procedure should prove to be a clinically valuable tool in crucial emergency situations.

Analysis of polybrominated biphenyls

High-performance liquid chromatography, gas chromatography-mass spectrometry, ultraviolet spectrometry and nuclear magnetic resonance spectrometry have been used to characterize the behaviour of a number of individual brominated biphenyls and to assess the composition of several mixtures of these compounds. The dependence of retention and spectral characteristics on the bromine content of the substituted biphenyls is discussed and the behaviour of polybrominated biphenyls is compared with that of polychlorinated biphenyls. The applicability of high-performance liquid chromatography to photodegradation studies is demonstrated.