Muhammad Aslam Mirza

Determination of uranium, iron, copper, and nickel in rock and water samples by MEKC.

A micellar electrokinetic capillary chromatographic (MEKC) procedure has been developed for the separation and determination of dioxouranium (VI), iron(III), copper(II), and nickel(II) using bis(salicylaldehyde)propylenediimine (H2SA2Pn) as chelating reagent with a total run time of <3 min. Sodium dodecyl sulphate (SDS) was used as micellar medium at pH 8.1 with sodium tetraborate buffer (0.1 M). Uncoated fused silica capillary with effective length 38.8 cmx75 microm id was used with an applied voltage of 30 kV and photo-diode array detection at 228 nm. Linear calibrations were established within 0.045-1000 microg/mL of each element with detection limit within 15-122 ng/mL. The method was applied to the analysis of spring water and rock samples. The presence of uranium in rock and spring water samples was established within 1.58-1739.3 microg/g and 0.047-0.712 microg/mL with relative standard deviation within 0.9-2.1% and 1.3-2.6% respectively. Uranium ore and water samples were also assayed by the standard addition technique. Recovery of uranium was >98% with RSD up to 2.7%. Copper, nickel, and iron in their combined matrix were concurrently determined within RSD 0.6-3.6% (n=5) and the results obtained were compared with those of flame AAS.

MEKC determination of vanadium from mineral ore and crude petroleum oil samples using precapillary chelation with bis(salicylaldehyde)tetramethyl- ethylenediimine

An analytical procedure has been developed for the separation of Cu(II), Ni(II), Co(II), Fe(II), Pd(II), Th(IV), V(IV), and determination of Fe(II), Co(II), Ni(II), and V(IV) by MEKC after chelation with bis(salicylaldehyde)tetramethylethylenediimine (H(2)SA(2)Ten). Uncoated fused silica capillary was used with an applied voltage of 30 kV with photo-diode array detection at 228 nm. SDS was added as micellar medium at pH 8.2 with sodium tetraborate buffer (0.1 M). Linear calibrations were established within 0.015-1000 microg/mL of each element with LOD within 5-67 ng/mL. The method was applied for the determination of vanadium from crude oil and ore samples in the range 0.34-2.40 and 114.2-720.7 microg/g with RSD 1.7-3.8 and 0.98-2.30% (n = 3), respectively. Fe, Ni, and Co present in crude oil and ore samples were also determined with RSD 1.3-2.8, 1.1-4.1, and 1.2-3.5% (n = 3), respectively. The results were compared with that of suppliers specifications and atomic absorption spectrometry (AAS). Method was evaluated by standard addition technique.

Synthesis and Structure of the Cyclic Borenium Cation 1,1,3,3-tetramethyl-1,3λ4,2-diazaborolidin-1-ium chloride

AbstractThe solid state structure of an N-heterocyclic borane 1,1,3,3-tetramethyl-1,3λ4,2-diazaborolidin-1-ium chloride is reported. This molecule features numerous Cl⋯H hydrogen bonds.Graphical AbstractThe crystal structure of 1,1,3,3-tetramethyl-1,3λ4,2-diazaborolidin-1-ium chloride shows multiple C–H⋯Cl interactions in the solid state.