NOPR Collection:

Separation of amino acids on alumina layer developed with oil-in-water microemulsion

Mon, 01 Oct 2001 00:00:00 GMT

Title: Separation of amino acids on alumina layer developed with oil-in-water microemulsion Authors: Mohammad, Ali; Agrawal, Vineeta Abstract: Oil-in-water microemulsion systems have been used as mobile phase in thin layer chromatographic separation of aliphatic and aromatic amino acids on plain (or non-impregnated) alumina and Li⁺, Na⁺ or NH₄⁺ - impregnated alumina layers. The results obtained with water and oil-in-water microemulsions have been compared. The lower limits of detection of amino acids have also been determined. Proline, dl-valine and dl- aspartic acid have been selectively separated from other amino acids. Page(s): 1130-1134

Separation and extractive spectrophotometric determination of palladium(II) with 5-methyl- 2,3-hexanedione dioxime

Mon, 01 Oct 2001 00:00:00 GMT

Title: Separation and extractive spectrophotometric determination of palladium(II) with 5-methyl- 2,3-hexanedione dioxime Authors: Tandel, Suhas P; Jadhav, Sanjeev B; Malve, Sheela P Abstract: 5-Methyl-2, 3-hexanedione dioxime (H₂MHDDO) is proposed as a new sensitive analytical reagent for the separation and extractive spectrophotometric determination of trace amounts of palladium(II). The reagent reacts with paliadium(II) in the pH range 0.5-1.5 to form a yellow co loured 1:2 chelate which is very well extracted in chloroform . Beer's law is obeyed in the concentration range 0.5-9.0 μg ml^-1 of palladium. The molar absorptivity of the extracted species is 3.894×10³l mol^-l cm^-1 at λ 379 nm. The proposed method is highly sensitive, simple, rapid and accurate and has been satisfactorily applied for the determination of palladium in synthetic mixtures, alloy, ore and catalysts. Page(s): 1128-1129

Trace determination of zirconium with 3-hydroxy-2-(2ʹ-thienyl)-4H-chromen-4-one by solvent extraction

Mon, 01 Oct 2001 00:00:00 GMT

Title: Trace determination of zirconium with 3-hydroxy-2-(2ʹ-thienyl)-4H-chromen-4-one by solvent extraction Authors: Nijhawan, Monica; Chhakkar, Anoop Kumar; Kakkar, Lajpat Rai Abstract: 3-Hydroxy-2-(2ʹ-thienyl)-4H-chromen-4-one forms a yellow coloured complex with zirconium at pH 8-8.2 which is quantitatively extracted into 1,2-dichloroethane with absorption maximum at 425nm. The method obeys Beer's law in the range 0-10 μg Zr(IV)/10ml and has a Sandell 's sensitivity of 0.0012μg Zr cm^-2. Page(s): 1124-1127

Simple and sensitive determination of nucleic acid by Rayleigh light scattering technique with methyl green-CTMAB

Mon, 01 Oct 2001 00:00:00 GMT

Title: Simple and sensitive determination of nucleic acid by Rayleigh light scattering technique with methyl green-CTMAB Authors: Liu, Rutao; Yang, Jinghe; Wu, Xia; Sun, Changxia Abstract: A method is presented for the determination of nucleic acid, based on the enhancement of Rayleigh light scattering (RLS) of methyl green (MG)-CTMAB in the pH range 6.9-7.2 at 414.0 nm. The enhanced intensity of RLS is proportional to the concentration of nucleic acid in the range 2.5×10^-8-2.0×10^-6g/ml for calf thymus (ct)DNA, 2.5×10^-8-2.0×10^-6g/ml for fish sperm (fs)DNA, 7.5×10^-8-2.0×10^-6g/ml for yeast (y)RNA. The detection limits (3σ) are 7.8, 2.6, 9.9 ng/ml for ctDNA, fsDNA and yRNA respectively. Besides its high sensitivity, it has some other advantages: simplicity of operation, commonality of spectrometer and reagents, good stability of chemical system and reproducibility. The procedure has been successfully applied to the determination of nucleic acid in synthetic samples. Page(s): 1121-1123