title: 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 Sb5+ to Sb3+ 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, HNO3 and water) used in the digestion were studied applying a constrained mixtures design. The optimal proportions found were 50% water, 25% HNO3 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 NaBH4 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.
authors: Departamento de Química e Exatas, Universidade Estadual do Sudoeste da Bahia, Rua José Moreira Sobrinho, s/n, 45206-191 Jequié, BA, Brasil.
authors: Manuelle C
authors: MC
authors: Cardozo
authors: Departamento de Ciências Exatas e da Terra, Universidade do Estado da Bahia, Rua Silveira Martins, 2555, 40170-290 Salvador, BA, Brasil.|Departamento de Química Analítica, Universidade Federal da Bahia, Instituto de Química, Rua Barão de Jeremoabo, 147, 40170-115 Salvador, BA, Brasil.
authors: Dannuza D
authors: DD
authors: Cavalcante
authors: Departamento de Ciências Exatas e da Terra, Universidade do Estado da Bahia, Rua Silveira Martins, 2555, 40170-290 Salvador, BA, Brasil.
authors: Daniel L F
authors: DL
authors: Silva
authors: Departamento de Ciências Exatas e da Terra, Universidade do Estado da Bahia, Rua Silveira Martins, 2555, 40170-290 Salvador, BA, Brasil.|Departamento de Química Analítica, Universidade Federal da Bahia, Instituto de Química, Rua Barão de Jeremoabo, 147, 40170-115 Salvador, BA, Brasil.
authors: Walter N L Dos
authors: WN
authors: Santos
authors: Departamento de Química e Exatas, Universidade Estadual do Sudoeste da Bahia, Rua José Moreira Sobrinho, s/n, 45206-191 Jequié, BA, Brasil.
authors: Marcos A
authors: MA
authors: Bezerra
mesh_terms: D000965:Antimony / Q000032:analysis* / Q000627:therapeutic use; D000981:Antiprotozoal Agents / Q000032:analysis* / Q000627:therapeutic use; D006197:Hair / Q000737:chemistry*; D006801:Humans; D007896:Leishmaniasis / Q000188:drug therapy*; D013050:Spectrometry, Fluorescence; D013054:Spectrophotometry, Atomic
chemical_list: D000981:Antiprotozoal Agents; C021254:stibine; D000965:Antimony