Multivariate optimization of a method for antimony determination by hydride generation atomic fluorescence spectrometry in hair samples of patients undergoing chemotherapy against Leishmaniasis

Abstract

A method was developed for determination of total antimony in hair samples from patients undergoing chemotherapy against Leishmaniasis based on the administration of pentavalent antimonial drugs. The method is based on microwave assisted digestion of the samples in a pressurized system, reduction of Sb 5+ to Sb 3+ with KI solution (10% w/v) in ascorbic acid (2%, w/v) and its subsequent determination by hydride generation atomic fluorescence spectrometry (HG-AFS). The proportions of each component (HCl, HNO 3 and water) used in the digestion were studied applying a constrained mixtures design. The optimal proportions found were 50% water, 25% HNO 3 and 25% HCl. Variables involved in the generation of antimony hydride were optimized using a Doehlert design revealing that good sensitivity is found when using 2.0% w/v NaBH 4 and 4.4 mol L -1 HCl. Under the optimum experimental conditions, the method allows the determination of antimony in hair samples with detection and quantification limits of 1.4 and 4.6 ng g -1 , respectively, and precision expressed as relative standard deviation (RSD) of 2.8% (n = 10 to 10.0 mg L -1 ). The developed method was applied in the analysis of hair samples from patients who take medication against Leishmaniasis.

Simple and rapid method for the determination of mercury in human hair by cold vapour generation atomic fluorescence spectrometry

“…However, an excess of HNO 3 in the final digested sample makes the reduction process inefficient because of the oxidation of the reducing agents [41,48]. Thus, the residual carbon content and residual acidity in final digests were determined.…”

“…Traditional CV systems may suffer from severe matrix interference from many coexisting transition metal ions [41,48,[71][72][73][74] because transition metals can, depending on their concentration, cause interference in the CV via parallel reactions with the reducing reagent (KBH ; two replicates) of C, respectively. A signal was considered free of interference when generated by a Hg standard solution in the absence of potential interfering elements; a value of 100% was attributed to this signal, and the IFS obtained in the presence of transition metals proportional to this value were calculated.…”

“…The use of CV atomic fluorescence spectrometry (AFS) is a good alternative for total Hg determination, and it has been used for the analysis of several food matrices [39]. Despite this, its use for hair analysis is documented only in very few works [3,19,40] for Sb [41] and other elements [20,[42][43][44][45]. In all these techniques, the sample must be introduced as a homogeneous liquid sample, and, thus, the digestion of the sample is necessary.…”

A Pyrene‐based Probe for Antimony with Special Excimer Fluorescence

“…Nowadays, lots of methods have been reported to be applied in the detection of antimony, such as atomic fluorescence spectrometry,, inductively coupled plasma mass spectrometry (ICP‐MS),, hydride generation atomic fluorescence spectrometry, and atomic absorption spectrometry , . However, the instruments are always with high cost and energy consumption, and the preparation of the materials need complex steps and long time, so new way should be found for simple and convenient detection of antimony.…”