اندازه گیری بیسموت و آنتیموان در فاز آلی پس از استخراج با دی بنزیل سولفوکسید از محیط یدیدی

all analytical methods are generally based on the measurement of a parameter or parameters which are somehow related to the concentration of the species.an ideal analytical method is one in which the concentration of a species can be measured to a high degree precision and accuracy and with a high sensitivity. unfortunately finding such a method is very difficult or sometimes even impossible.interference of various parameters and their interaction makes it difficult to find of a selective method for an element.thus in most analytical methods a preliminary separation is needed before the actual measurement can be made. the purpose of performing any separation is to eliminate interfering factors and to increase the sensitivity of our measurement.extraction is one of the most common separation methods.both from a theoretical and an experimental viewpoint,this method has a rich scientific background.for example consider the measurement of bismuth,one of the best methods is the conversion of bismuth to the colored complex.bii4- , and the photometric measurement of the absorption of this species.but even this precise and sensitive method have interfering factors,that in practice make the analysis unfeasible.lead , iron , copper , palladium , platinum , tellurium , antimony , barium , silver , nickle , fluoride , and other factors interfere with this measurement. but to measure bismuth we must separate these factors.a simple separation method must be developed or a method developed in which bismuth may be measured in the presence of these interferences.in this paper the extraction of the iodide complexes of bismuth and antimony by dibenzylsulfoxide is studied as stated the goal is the measurement of antimony and bismuth in the presence of interferences.all factors effecting the extraction or complex formation were optimized by use of statistical methods like factorial design and simplex optimization.then by obtaining a calibration curve at a optimum condition,the bismuth in the organic phase was measured.this method was extracted into the organic phase and the interfering factors were thus eliminated.the linear dynamic range of the measurement was between 0.5 and 25 ppm,which is comparable to the more sensitive and expensive methods of bismuth determination,e.g. atomic absorption.in the case of antimony the method used was similar to those used for bismuth,but computer aided statistical analysis was used in this case.a new wavelength of maximum absorption was also fond for the antimony iodide complex which was hitherto unstated in previous work.the linear dynamic range for antimony was 0.2 ppm to 1.8 ppm which shows the high sensitivity of this method.this method was used in synthetic real samples,the interval of confidence and standard deviation were found to be appropriate.