A new ultrasonic method to detect chemical additives in branded milk

A new ultrasonic method — thermoacoustic analysis — is reported for the detection of the added chemical preservatives in branded milk. The nature of variation and shift in the thermal response of the acoustic parameters specific acoustic impedance, adiabatic compressibility and Rao’s specific sound velocity for different samples of branded milk as compared to the chemical added pure milk are explained as due to the presence of chemicals in these branded samples.     

Cerium(IV) ammonium nitrate (CAN)-mediated sulfonylation of styrenes: some interesting observations

Sulfonyl radicals generated by the oxidation of sodium arylsulfinates with cerium(IV) ammonium nitrate (CAN) undergo addition reaction with styrenes to give the sulfonylated products in good yields.     

A simple field test for the detection of mercury in polluted water, air and soil samples

Summary A simple field test for the detection of mercury is described. The test is based on the ligand exchange reaction where hexacyanoferrate(III) exchanges its cyanide ions with chromogenic organic ligand succinyl dihydroxamic acid (SDHA). In the reaction the colourless SDHA reacts with yellow K₃Fe(CN)₆ to give a greenish blue coloured complex in a slightly acidic solution containing mercury. The reaction has been successfully applied for the detection of mercury in polluted water, air and soil samples. In air, at a velocity of 0.21/min of the impinging air and a reaction temperature of 70°C, mercury(II) as low as 0.01 g could be easily detected after 3 min exposure. In water the limit of identification and limit of dilution were found to be 0.2 g Hg(II) and 1:200000, respectively.     

Oxidative cyclisation of cinnamyl ethers mediated by CAN: a stereoselective synthesis of 3,4-trans disubstituted tetrahydrofuran derivatives

The oxidative cyclisation of cinnamyl ethers mediated by cerium(IV) ammonium nitrate results in the stereospecific formation of 3,4-trans disubstituted tetrahydrofuran derivatives in moderate to good yields.     

IR,Raman and SERS spectra of ethyl salicylate

The IR and Raman spectra of ethyl salicylate were recorded and analyzed. The surface enhanced Raman scattering (SERS) spectrum was recorded in a silver colloid. The vibrational wavenumbers of the compound have been computed using the Hartree‐Fock/6‐31G* basis. The direction of charge transfer contribution to SERS has been discussed from the frontier orbital theory. The presence of methyl modes in the SERS spectrum indicates the nearness of the methyl group to the metal surface and the presence of ring vibrations and out‐of‐plane ring modes in the SERS spectrum suggests a flat orientation of the molecule on the silver surface. The first hyperpolarizability is calculated and the calculated molecular geometry has been compared with the reported similar structures. Copyright © 2009 John Wiley & Sons, Ltd.     

Vibrational spectroscopic studies and DFT calculations of 4‐fluoro‐N‐(2‐hydroxy‐4‐nitrophenyl)benzamide

Fourier transform infrared (FT‐IR) and FT‐Raman spectra of 4‐fluoro‐N‐(2‐hydroxy‐4‐nitrophenyl)benzamide were recorded and analyzed. The vibrational wavenumbers and corresponding vibrational assignments were examined theoretically using the Gaussian03 set of quantum chemistry codes. The red‐shift of the NH‐stretching wavenumber in the infrared (IR) spectrum from the computed wavenumber indicates the weakening of the NH bond resulting in proton transfer to the neighboring oxygen atom. The simultaneous IR and Raman activation of the CO‐stretching mode gives the charge transfer interaction through a π‐conjugated path. Copyright © 2008 John Wiley & Sons, Ltd.