The development and implementation of quality assurance programs to support nutritional measurements.

The National Institute of Standards and Technology administers quality assurance programs devoted to improving measurements of nutrients and related metabolites in foods, dietary supplements, and serum and plasma samples. These programs have been developed in collaboration with the National Institutes of Health to assist measurement communities in their efforts to achieve accurate results that are comparable among different laboratories and over time. Targeted analytes include micronutrients, botanical markers, nutritional elements, contaminants, fatty acids, and vitamin D metabolites.

Development and certification of green tea-containing standard reference materials.

A suite of three green tea-containing Standard Reference Materials (SRMs) has been issued by the National Institute of Standards and Technology (NIST): SRM 3254 Camellia sinensis (Green Tea) Leaves, SRM 3255 Camellia sinensis (Green Tea) Extract, and SRM 3256 Green Tea-Containing Solid Oral Dosage Form. The materials are characterized for catechins, xanthine alkaloids, theanine, and toxic elements. As many as five methods were used in assigning certified and reference values to the constituents, with measurements carried out at NIST and at collaborating laboratories. The materials are intended for use in the development and validation of new analytical methods, and for use as control materials as a component in the support of claims of metrological traceability.

Certification of standard reference materials containing bitter orange.

A suite of three dietary supplement standard reference materials (SRMs) containing bitter orange has been developed, and the levels of five alkaloids and caffeine have been measured by multiple analytical methods. Synephrine, octopamine, tyramine, N-methyltyramine, hordenine, total alkaloids, and caffeine were determined by as many as six analytical methods, with measurements performed at the National Institute of Standards and Technology and at two collaborating laboratories. The methods offer substantial independence, with two types of extractions, two separation methods, and four detection methods. Excellent agreement was obtained among the measurements, with data reproducibility for most methods and analytes better than 5% relative standard deviation. The bitter-orange-containing dietary supplement SRMs are intended primarily for use as measurement controls and for use in the development and validation of analytical methods.

A comparison of peer-directed and teacher-directed employment interview training for mentally retarded adults.

Interview skills deficits may limit employment prospects of mentally retarded adults. Although numerous papers highlight the importance of interview skills, few have validated effective strategies for use with mentally retarded persons. Further, there has been a lack of research contrasting rival interview skills training strategies. The present study was conducted with two mentally retarded young adults. It contrasted peer-directed instruction, in which both participants were equally deficient in the target skills, with teacher-directed instruction. Results of the investigation indicated that instruction, rehearsal, and feedback may be effective strategies regardless of who provides instruction. Comparisons of teacher-directed and peer-directed instruction indicated little or no difference in the effectiveness of the two procedures. However, the peer-directed procedure involved considerably less staff time than did the teacher-directed procedure.