a simple and rapid spectrophotometric method for the determination of nitrite in water and soil preparation samples has been developed. determination of nitrite is based on diazotization of p-nitro aniline with nitrite and subsequent coupling with 4-amino-3-hydroxynaphthalene-1-sulfonic acid in hydrochloric acid. the factors affecting the reaction i.e. concentration of p-nitro aniline, concentr...

Perfluoroalkyl acids (PFAAs) are a group of persistent organic substances that are surface active and water and fat/oil repellent. Due to the wide use and persistence of PFAAs they are present everywhere in the environment, and humans are exposed via food, drinking water and the use of products containing PFAAs and related compounds. We investigated blood serum levels of ten perfluoroalkyl carb...

sulfonic acid functionalized sba-15 (sba-pr-so3h) as a new nanoporous acid catalyst was used in the one-pot synthesis of polyhydroquinolines derivatives via the hantzsch four component condensation reaction of aldehydes, b-ketoesters, dimedone and ammonium acetate under solvent free conditions with short reaction time in excellent yields. sba-pr-so3h was proved to be an efficient heterogeneous ...

The differential scanning colorimetry (DSC) thermooxidative stability of new copolymers styrene-sulfonic acid and N-vinylimidazole obtained by radical copolymerization in a DMF solution an argon atmosphere has been studied

In this work, we report the synthesis of a combinatorial library of 80 derivatives of EDTA amide x-aminenaphthalene-y-sulfonic acid on four different supports with variable length linker. The sensing fluorescence behavior of these materials for transitions metals was studied by packing the beads into a conventional flow-through cell in a continuous flow injection set up. The fluorescence emissi...

Results Among fifteen PFCs analyzed, perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) were detected in >90% of the serum samples. The number of chemicals above median concentrations among these 5 PFCs were graded on a scale of 0 to 5, and classified into exposure (0) (...