a pvc membrane cr(iii) ion selective electrode has been constructed using 2h-1,4-benzothioazine-2,3(4h)dione dioxime (btd) as membrane carrier. the influence of membrane composition on the electroderesponse was studied. the electrode exhibits a nernstian response over a cr(iii) concentration range of 1.0 x10 6 to 1.0>< 10-1 m (r = 0.99) with a slope of 19.5 ± 0.5 mv per decade of concentration,...

a simple, rapid and sensitive method has been developed for determination of trances of tellurium (vi) (0.096-1.250 mg/ml) based on its catalytic effect on the reduction reaction of toluidine blue by sulfide ion at ph 4. the reaction is monitored spectrophotometrically by measuring the decrease in absorbance of the dyestuff at 628 nm by the fixed time method. the detection limit is 80 ng/ml and...

a sensitive and selective extraction - spectrophotometric method for the determination of trace amounts of palladium is reported. the method is based on quantitative extraction of brownish tetrabutylammoium tetraiodopalladium (ii) ion pair into a small valume of chloroform at ph 1.3-12.0, followed by spectrophotometric measurements. the beer's law is obeyed over the range 0.02-1.09 mgml-1 at 44...

a spectrophotometric method for selective complexation reaction and simultaneous determination of mycophenolate mofetil (mpm), and mycophenolic acid (mpa) using three multivariate chemometric methods, i.e. partial least squares regression, principal component regression and principal component artificial neural networks, is proposed. the method is based on the complexation reaction of mpm and m...

background and purpose: islamic republic of iran has greatly reduced its malaria burden and has a national goal to eliminate malaria by 2025. the aim of this study was to determine the population dynamics of anopheles maculipennis sensu lato, in relation to probable malaria transmission. for this purpose, the study was conducted in three villages in isfahan province of iran, from april to march...

lead forms the complexes with xylenol orange in the basic solution. an adsorptivedifferential pulse stripping method for the determination of lead is proposed. the procedureinvolves an adsorptive accumulation of lead on a hanging mercury drop electrode (hmde) inthe presence of xylenol orange, followed by reduction of adsorbed lead by voltammetric scanusing differential pulse modulation. the opt...

The present article reports on the application of modified organo nanoclay as a green, easily prepared and stable solid sorbent for the preconcentration of trace cobalt ion in aqueous solution. The organo nanoclay was modified by adsorption of 5-(4-dimethyl amino-benzylidene) rhodanin reagent onto it. The sorption of Co2+ ions was quantitative in the pH range of 7.0 to 8.5, whereas quantitative...

7. 1. Summary Vertebrates have various sex determining mechanisms. These have been broadly classified as either genotypic sex determination (GSD) or environmental sex determination (ESD). This terminology, however, may obscure the fact that mixtures between genotypic and environmental sex determination exist, or that genotypic and environmental sex determination may, in fact, be the extremes of...