Theoretical analysis and Computer simulations have proven to be cost-effective and powerful tools in scientific studies of materials, particularly at nano-scale where synthesis of nano-structures, interpretation of their observed character and exploration of new structures are not always straight forward. We present here fundamental principles of techniques used today for computational simulati...

A simple and sensitive spectrophotometric method combined with solid-phase extraction (SPE) for the simultaneous determination of sodium linear-dodecylbenzenesulfonate (DBS) and sodium dodecyl sulfate (SDS) is described. The C2 (ethyl group bonded silicagel) cartridge could be repeatedly used more than 500 times for SPE, and it enabled the anionic surfactants to be concentrated by 50-fold. The ...

Metabolic carboxylic acids are extracted, with a mixture of equal volumes of t-amyl alcohol-chloroform, from an acidifiedsample of as littleas 200 tI of urine that has been adsorbed to a short column of silicagel. Total acid in the extract is measured by titrationwith tetramethylammonium hydroxide (10 mmol/liter) to a phenolphthalein end point.There is no interferencefrom protein,creatinine, cr...