The title compound, (C(5)H(6)N(3)O(2))(2)[Cr(2)O(7)], consists of 2-amino-3-nitro-pyridinium cations and discrete dichromate anions linked together by N-H⋯O and C-H⋯O hydrogen bonds, forming thick layers parallel to (101). Layer cohesion is ensured by N-H⋯O hydrogen bonding in addition to electrostatic and van der Waals inter-actions, forming a three-dimensional framework. The dichromate anion ...

Two commercial samples of saffron were analysed for moisture and ash contents, solubility in water, action with sulphuric acid, presence of foreign dyes and colour intensity of water soluble solution.The moisture content in Laccha was 12.7% while it was 11% in Mogra. The ash was 4.7% in both the samples. The water soluble matter in Laccha was 52.7% and 45.8% in Mogra. There was no foreign dye i...

A PVC membrane incorporating p-tert-butyl calix[4]crown with imine units as an ionophore was prepared and used in an ion-selective electrode for the determination of mercury(II) ions. An electrode based on this ionophore showed a good potentiometric response for mercury(II) ions over a wide concentration range of 5.0 x 10(-5) - 1.0 x 10(-1) M with a near-Nernstian slope of 27.3 mV per decade. T...

The title compound, (C(3)H(12)N(2))[Cr(2)O(7)], consists of a discrete dichromate anion with an eclipsed conformation and a propane-1,3-diammonium cation. Both kinds of ions have a mirror plane passing through the bridging O atom and the central methyl-ene C atom of the Cr(2)O(7) (2-) and C(3)H(12)N(2) (2+) moieties, respectively. Anions and cations are alternately stacked to form columns paral...

We describe a rapid method for calibrating the Technicon AutoAnalyzer colorimeter I. Test solutions of bromphenol blue are recommended for the calibration, in preference to solutions of potassium dichromate, based on considerations of the instrument's working range and of the stray light characteristics of the associated filters.

Stool is chemically complex and the extraction of DNA from stool samples is extremely difficult. Haemoglobin breakdown products, such as bilirubin, bile acids and mineral ions, that are present in the stool samples, can inhibit DNA amplification and cause molecular assays to produce false-negative results. Therefore, stool storage conditions are highly important for the diagnosis of intestinal ...

We introduce the ``trivariate Tutte polynomial" of a signed graph as an invariant graphs up to vertex switching that contains among its evaluations number proper colorings and nowhere-zero flows. In this, it parallels polynomial graph, which chromatic flow specializations. The tensions (for they are not simply related for graphs) is given in terms trivariate at two distinct points. Interestingl...