Influence of thiocyanate ions on starch-iodine reaction used for the estimation of alpha-amylase activity

Radioactive iodine capture and storage from water using magnetite nanoparticles encapsulated in polypyrrole

The effective capture and storage of radioactive iodine is of importance for nuclear waste storage during nuclear power station accidents. Here we report Fe₃O₄@PPy powder containing ∼12nm magnetite (Fe₃O₄) nanoparticles encapsulated in the polypyrrole (PPy) matrix. It shows 1627mg/g uptake of iodine dissolved in water, within 2h at room temperature. Fe₃O₄@PPy is ferromagnetic in nature and can be separated from water using external magnetic field. The nitrogen gas sweeping test at 30°C shows release of 2% iodine from iodine adsorbed Fe₃O₄@PPy, revealing stable storage of iodine for a moderate period. The iodine-adsorbed magnetic powder can be regenerated by washing with ethanol. The XPS spectrum of iodine adsorbed Fe₃O₄@PPy confirmed the presence of polyiodides (I₃^- and I₅^-) bound to the PPy surface. This excellent iodine capture and storage from iodine contaminated water is an environment friendly, inexpensive and large scale method.

Amylase measurement with 2-chloro-4-nitrophenyl maltotrioside as substrate

The use of 2-chloro-4-nitrophenyl maltotrioside (CNP-G3) as substrate to measure amylase (EC 3.2.1.1) activity in serum directly without the use of auxiliary enzymes was evaluated at two centres. The method was precise (within-run C.V. < 2% and between-run C.V. < 3%), there was no lag phase, background absorbance was low and there were minimal effects of pH changes. When compared with a method which uses 4,6-ethylidene (G7)-p-nitrophenyl (G1)-alpha-D-maltoheptaoside (EPS-G7) as substrate, the CNP-G3 method had greater sensitivity and longer reagent stability (21 days compared with 2 days at 4 degrees C). The activity measured with the CNP-G3 method correlated well with methods using either EPS-G7 and maltotetraose as substrates.

A new method for locating saliva stains-spotty paper for spotting spit

A convenient method of locating saliva stains has been devised. Filter paper covered with blue coloured starch fragments is laid on the material to be tested. Salivary amylase hydrolyses the starch on the areas of paper corresponding to saliva stains, which are then delineated as clear zones whereas negative areas remain speckled with blue particles.