Electrothermal atomic absorption spectrometric determination of lead, cadmium, copper and zinc in high-salt content samples after simultaneous separation on polyethylene powder impregnated with 1-(2-pyridylazo)-2-naphthol: application to the analysis of hemodialysis fluids

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A determinação sequencial de cromo, tálio, cádmio, chumbo, cobre e antimônio em concentrados polieletrolíticos para hemodiálise (DCs) é apresentada. Cromo foi determinado usando voltametria adsortiva de redissolução catódica e tálio, cádmio, chumbo, cobre e antimônio por meio de voltametria de redissolução anódica. O novo método desenvolvido para testar estas amostras se baseia no efeito do gradiente de pH do eletrólito na resposta voltamétrica. Os limites de detecção variaram de 0,03 mg L -1 para cádmio a 0,27 mg L -1 para cobre. Recuperações das amostras variaram de 92,0 a 117,5%. Este método foi aplicado para a análise de DCs comerciais, nos quais as concentrações encontradas dos analitos variaram de 0,16 mg L -1 para antimônio até 140,00 mg L -1 para cobre. Interferências e método de referência são discutidos.The sequential voltammetric determination of chromium, thallium, cadmium, lead, copper and antimony in dialysate concentrates (DCs), is presented herein. Chromium was quantified by adsorptive cathodic stripping voltammetry and thallium, cadmium, lead, copper and antimony were assayed by anodic stripping voltammetry. The novel method developed to test these samples exploits the effect of electrolyte pH gradient on voltammetric response. The limits of detection (LOD) ranged from 0.03 mg L -1 for cadmium to 0.27 mg L -1 for copper. Recoveries from spiked samples were 92.0-117.5%. This method was applied to the analysis of commercial DCs, where the investigated metals were found in some samples at concentrations between 0.16 mg L -1 for antimony and 140.00 mg L -1 for copper. Interferences and the reference method are discussed.

Section: Methods Validationmentioning

confidence: 99%

Section: Thallium Cadmium Lead and Coppermentioning

confidence: 99%

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Sequential voltammetric determination of chromium, thallium, cadmium, lead, copper and antimony in saline hemodialysis concentrates using electrolyte pH gradient

Nascimento

Schneider

Bohrer

et al. 2011

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“…In the low level we found again the same anionic species and also aluminum in some samples. In the same way, commercial HS solutions should be free of contaminants but in a previous work 51 we found Cu, Zn, Pb and Cd as contaminants at µg L -1 levels in commercial HS solutions. The origin of this contamination was attributed to the salts used in the production of the HS solutions.…”

Section: Interferencesmentioning

confidence: 99%

Determination of triazines in hemodialysis saline solutions by adsorptive stripping voltammetry after extraction in acetonitrile

Nascimento¹,

Bohrer²,

Carvalho³

et al. 2003

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A determinação de herbicidas 2-metiltio-4,6-dialquilamino-1,3,5-triazina (triazinas) em soluções salinas utilizadas em hemodiálise foi investigada por voltametria. Os herbicidas foram detectados com grande sensibilidade nas soluções salinas, após extração em fase de acetonitrila (ACN), utilizando o eletrodo de mercúrio de gota pendente. O efeito de salting out originado pelo meio salino existente nas soluções viabilizou as extrações. A relação de volumes entre as fases salina e de ACN foi investigada para alcançar a melhor sensibilidade na detecção das triazinas. A especiação entre as triazinas investigadas (ametrina, desmetrina, prometrina e terbutrina) não foi possível e recuperações entre 88 e 107% foram calculadas em amostras fortificadas com os analitos. Utilizando esta metodologia, limites de detecção de 0,03 µmol L -1 foram calculados para as triazinas nas amostras salinas.A method for the voltammetric determination of 2-methylthio-4,6-dialkylamino-1,3,5-triazine (triazines) herbicides in hemodialysis (HD) saline solutions was developed. The herbicides were detected in the saline solutions at the hanging mercury drop electrode (HMDE) with high sensitivities only after extraction of the analytes in acetonitrile (ACN). The salting out effect originated by the saline environment existing in the solutions enabled the extractions. The volume ratio between the saline and ACN phases was investigated in order to find the best sensitivity to detect the triazines. The speciation amongst them (ametryn, desmetryn, prometryn and terbutryn) was not possible. Recoveries between 88 and 107% were calculated in spiked samples, and detection limits of 0.03 µmol L -1 were calculated for the triazines in the saline samples using this methodology. Keywords: herbicides, triazines, hemodialysis, voltammetry IntroductionThe growing interest in the use of pesticides in agricultural production and their negative environmental impact has led to a number of studies for the development of different analytical methods. Besides the frequently used chromatographic measurements, voltammetry, mainly with differential pulse modes 1-9 should be taken into consideration as a fast, easy and inexpensive alternative. Additionally, the sensitivity of the electrochemical methods, their applicability over an unusually wide concentration range, is highly satisfactory for meeting requirements of toxicological, ecotoxicological and environmental regulation enforcement. 10 Hemodialysis (HD) solutions are prepared by mixing pure water and a high-salt (HS) content solution (about 7.0 mol L -1 ) to compose the final HD solution that has a salt concentration of about 0.2 mol L -1 . It is used to maintain the blood ionic equilibrium of the patients during the hemodialysis sessions. The presence of contaminants in the water or in HS solutions must be detected before a hemodialysis session as the HD solution remains very close to the blood of the patients separated only by the dialysis membranes. To aggravate the problem, the dialysis membranes can dialysate ...

“…In previous works, we showed that the contamination of hemodialysis patients by toxic metals such as Al, As, Zn, Pb, Cd and Tl can be related to their presence in dialysis concentrates or water used for the preparation of dialysis fluids. [2][3][4][5][6][7][8][9] Besides, Lee and co-workers 1 reported that the contamination of hemodialysis patients could be also related to the medication used in the treatment of anemia, such as the renal antianemic human recombinant erythropoietin (EPO).…”

Section: Introductionmentioning

confidence: 99%

Determination of metallic contaminants in human recombinant erythropoietin (EPO) formulations by adsorptive cathodic stripping voltammetry and UV photo-decomposition of samples

Carvalho¹,

Garmatz²,

Spengler³

et al. 2010

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A contaminação de pacientes com insuficiência renal por espécies metálicas pode estar associada a presença destes na medicação empregada durante o tratamento. Dentre os possíveis contaminantes estão metais nefrotóxicos tais como alumínio, cromo e níquel. No presente trabalho, a presença de Al, Cr e Ni como contaminantes em formulações de eritropoetina (EPO) foi investigada através da otimização de métodos analíticos empregando a voltamétria adsortiva de redissolucao catódica (AdCSV) associada a foto-decomposição de amostras com radiação UV. A irradiação UV de amostras acidificadas de EPO pelo período de 2 a 3 horas na presença de H 2 O 2 possibilitou a decomposição eficiente da amostra e a determinação dos contaminantes por AdCSV sem a interferência da matriz. O método otimizado foi aplicado na determinação dos metais em formulações comerciais de EPO utilizadas rotineiramente no tratamento da anemia em pacientes com insuficiência renal crônica. Os níveis de contaminação encontrados nas amostras estudadas variaram de 420,2 a 840,5 ng mL -1 (RSD 2-5%) para o Al, de 12,0 a 40,0 ng mL -1 (RSD 2-6%) para o Cr e de 4,1 a 8,2 ng mL -1 (RSD 3-8%) para o Ni. Os resultados obtidos por AdCSV foram comparáveis aos obtidos por espectrometria de absorção atômica com atomização em forno de grafite (GFAAS). A contaminação de formulações EPO com Al, Cr e Ni mostrou ser uma fonte de contaminação importante para pacientes anêmicos com insuficiencia renal crônica.The contamination of renal failure patients by metals can be associated to the presence of toxic metals in the medication, since they can be absorbed by the organism. Among the possible contaminants, there are nephrotoxic metals such as aluminum, chromium and nickel. In the present work, the presence of Al, Cr and Ni as contaminants in erythropoietin formulations (EPO) was investigated by optimizing the adsorptive cathodic stripping voltammetric (AdCSV) method and the photo-decomposition of samples by UV irradiation. The UV irradiation of acidified EPO samples from 2 to 3 h in the presence of H 2 O 2 allowed the efficient sample decomposition and the determination of the contaminants by AdCSV without matrix interferences. The method was applied for the determination of the metals in commercial EPO formulations used routinely in the treatment of anemia in patients undergoing chronic renal failure. The contamination levels determined in the samples ranged from 420.2 to 840.5 ng mL -1 (RSD 2-5%) for Al, 12.0 to 40.0 ng mL -1 (RSD 2-6%) for Cr and 4.1 to 8.2 ng mL -1 (RSD 3-8%). The results obtained by AdCSV were in good agreement with those obtained by the comparative GFAAS measurements. The contamination of EPO formulations with Al, Cr and Ni was shown to be a serious contamination source for anemic patients undergoing chronic renal failure.Keywords: adsorptive cathodic stripping voltammetry, UV irradiation, photo-decomposition, erythropoietin IntroductionChronical renal failure causes a wide variety of metabolic disturbances which affect almost every organ in the body syst...