An in situ single-drop microextraction (SDME) method was developed for trace mercury determination by a miniaturized spectrophotometer, in which a simple and cheap light-emitting diode (LED) was employed as the light source, and a handheld charge coupled device (CCD) was served as the detector. A droplet of 0.006% dithizone-CCl(4) (m/v) was used as extraction phase and hanged on a rolled PTFE t...

Lead measurementsby direct AAS at 217 nm on a pooled urine sample gave values of 57 pg/i by the method of standard additions. In contrast, dithizone procedures gave values of 15-20 pg/i. Studies demonstrated that various urine salts and organic compoundscontributed to the absorbance at 217 nm. These native urine materials also give a similar absorbancevalue at 220 nm, a line not related to lead...

In the title compound, C(15)H(14)N(4)O(2)S·0.4C(3)H(6)O·0.1CH(2)Cl(2), two benzene rings in the ortho-meth-oxy dehydro-dithizone (omd) mol-ecule are twisted out of the tetra-zole plane with the meth-oxy groups in a cis orientation relative to the tetrazole backbone. The acetone is located on a special position. The dihedral angles formed by the benzene rings with the central five-membered ring ...

The role of indigenous and non-indigenous arbuscular mycorrhizal fungi (AMF) on As uptake by Plantago lanceolata L. growing on substrate originating from mine waste rich in As was assessed in a pot experiment. P. lanceolata inoculated with AMF had higher shoot and root biomass and lower concentrations of As in roots than the non-inoculated plants. There were significant differences in As concen...

Metal catalyst free carbon nanotube (MCFCNT) whiskers were first used as an electrode modification material on a gold electrode surface for zinc voltammetric measurements. A composite film of Nafion and MCFCNT whiskers was applied to a gold electrode surface to form a mechanically stable sensor. The sensor was then used for zinc detection in both acetate buffer solution and extracted bovine ser...

A procedure whereby reflectance spectroscopy can be employed for the analysis of substances resQlved on thinlayer plates was developed with the use of metal cation mixtures that had been separated on cellulose plates. A rapid method was devised whereby fourteen cations were separated and identified ~~ by their reflectance spectra after chromogenesis with a mixture of dithizone and 8-hydroxyquin...

Diazotization of 3-amino-2-cMoro pyridine (3) in the presence of dithizone (5) gave dphenyl-2-phenylazo-4H-pyrid[o3 ,2-e] [1,3,4] thiadiazine (6). Reaction of 2- chloro-3-nitropyridine (2, G=H) with (5) dfordd 4-phenyl -2-phenylazo -4Hpyrido [2,3-el [1,3,4] thiadiazine (7). Reduction of the latter with H gas in the presence of Raney nickel gave the corresponding amino derivative (12). One ...

A micell-mediated phase separation method for preconcentration of ultra-trace quantities of mercury as a prior step to its determination by UV-Vis spectrophotometry has been developed. The method is based on Hg(II)-dithizone complex formation in alkaline aqueous solution, and extraction of this Hg(II)-dithizone secondary complex into the surfactant-rich phase of the non-ionic surfactant oct...