Toxaphene: a challenging analytical problem.

The analysis of toxaphene, a highly complex mixture of chlorinated bornanes, bornenes and camphenes, is a challenging problem, especially as individual congeners are present at trace levels in biota and other relevant samples. The complicated nomenclature of the compounds of interest is briefly discussed. Gas chromatographic techniques are the most important tools in toxaphene analysis because of their high resolution. The main focus of attention is devoted to important steps in the GC-based analytical procedure, such as sample preparation and injection, separation by single-column and multidimensional GC, both heart-cut and comprehensive, and detection by electron capture and, increasingly, MS-based detection/identification. The gradual shift from total toxaphene to individual compound analysis is discussed, and the growing interest in enantiomer-selective separations is highlighted. The problems encountered when selecting appropriate indicator compounds for rapid toxaphene screening are also addressed.

Subtest profiles of the WISC-R and WAIS in mentally retarded patients with epilepsy.

In this study, WISC-R and WAIS subtest profiles of mentally retarded patients with epilepsy are analysed with respect to the Verbal-Performance IQ Discrepancy scores and rank order of mean subtest scores. The relative strengths and weaknesses in cognitive patterns of this sample are compared with subtest profiles mentioned in the literature on mentally retarded populations and samples of normal intelligent patients with epilepsy in order to determine the impact of epilepsy factors on cognition. The results indicate that people with mental retardation have problems with the verbal subtests Arithmetic, Vocabulary and Information, while patients with epilepsy have problems with Coding (Digit Symbol), Digit Span and Information. For this sample of mentally retarded patients with epilepsy, the most difficult subtests are Digit Span and Coding. The results concerning subtest profiles in different populations are discussed in light of the deleterious impact of epilepsy on cognition, which may superimpose the general effect of brain damage in mentally retarded patients. It is suggested that especially attentional processes, as measured with the subtest Coding, are vulnerable for epilepsy factors.