Simultaneous determination of palladium, platinum and rhodium by on-line column enrichment and HPLC with 2,4-dihydroxybenzylidenethiorhodanine as pre-column derivatization reagent

Abstract

Um novo método para determinação simultânea de íons paládio, platina e ródio, como quelatos metal-DHBTR foi desenvolvido. Os íons paládio, platina e ródio foram derivatizados (pré-coluna) com 2,4-dihidroxibenzilidenotiorodanina (DHBTR) para formar quelatos coloridos. Os quelatos Pd-DHBTR, Pt-DHBTR e Rh-DHBTR são absorvidos na coluna de enriquecimento, quando injetados e transportados por uma fase móvel composta por solução tampão de ácido acético-acetato de sódio 0,05 mol L -1 (pH 3,5). Após o término do enriquecimento, ao acionar uma válvula de seis vias, os quelatos retidos foram carregados pela fase móvel, para a coluna analítica. A separação dos quelatos na coluna analítica foi satisfatória com acetonitrila 62% (v/ v) (contendo solução tampão de ácido acético-acetato de sódio (0,05 mol L -1 , pH 3,5) e 0,1% (m/v) de tritonX-100) como fase móvel. Os limites de detecção de paládio, platina e ródio são 3,6 ng L -1 , 3,2 ng L -1 e 4,5 ng L -1 , respectivamente. Este método foi aplicado para a determinação de paládio, platina e ródio em água, urina e amostras de solo, com bons resultados.A new method for the simultaneous determination of palladium, platinum and rhodium ions as metal-DHBTR chelates was developed. The palladium, platinum and rhodium ions were pre-column derivatized with 2,4-dihydroxybenzylidenethiorhodanine (DHBTR) to form colored chelates. The Pd-DHBTR, Pt-DHBTR and Rh-DHBTR chelates can be absorbed onto the front of the enrichment column when they were injected into the injector and sent to the enrichment column with a 0.05 mol L -1 sodium acetate-acetic acid buffer solution (pH 3.5) as mobile phase. After the enrichment had finished, by switching the six ports switching valve, the retained chelates were back-flushed by mobile phase and traveling towards the analytical column. These chelates separation on the analytical column was satisfactory with 62% (v/v) acetonitrile (containing 0.05 mol L -1 of pH 3.5 sodium acetate-acetic acid buffer salt and 0.1% (m/v) of tritonX-100) as mobile phase. The Limits of detection of palladium, platinum and rhodium are 3.6 ng L , respectively. This method was applied to the determination of palladium, platinum and rhodium in water, urine and soil samples with good results.Keywords: palladium, platinum, rhodium, 2,4-dihydroxybenzylidenethiorhodanine, high performance liquid chromatography, on-line enrichment IntroductionEnvironmental contamination by the platinum group elements (PGEs), mainly related to automotive catalytic converters, is exponentially increasing and reliable and accurate quantification is a mandatory task. [1][2][3][4] The wide use of palladium, platinum and rhodium not only in automotive catalytic converters but as a drug (Pt) and in food production (Pd) 5 has led to a more uncontrolled release of those metals in the environment, with respect to the one due to the traditional chemical industry. Moreover, the platinum group elements derived from automotive catalytic converters are released as nanocrystallites (particles with less than 3 mm in ...

Redox behavior and adsorptive cathodic stripping voltammetric determination of nanomolar levels of palladium using a novel Schiff base reagent containing a squaric acid moiety

“…3 Thus, the development of analytical techniques for analysis of PGEs including Pd is growing because of their applications in medicine, micromechanics and chemical engineering. Because of Pd toxicity, 4 the frequency at which even trace levels of this metal are being monitored in surface waters, soil surfaces, plants and particulate matter has been rapidly increasing. The low level of Pd together with the high concentration of interfering matrix components oen requires a preconcentration step combined with a matrix separation.…”

Optimized and validated spectrophotometric method for the determination of palladium(II) in synthetic mixture and automobile workshop area samples

“…Therefore, because of its increasing use and also due to toxicity of palladium(II) compounds to mammals, fish and higher plants (Lee, 1983), the determination of this pollutant in environmental matrices is of considerable importance for human exposure assessment and for the investigation of correlations with health effects. Several analytical methods have been reported based on atomic absorption spectrometry (Cetin et al, 2013;Tillery and Johnson, 1975;Tokalioglu et al, 2004;Chwastowska et al, 2004;Rojas et al, 2006;Liang et al, 2009), inductively coupled plasma spectrometry (Moldovan et al, 2003), differential pulse polarography (Dias and Nozaki, 1998), high performance liquid chromatography (Dong et al, 2006), derivative spectrophotometry (Vojkovic and Druskovic, 2003;Kumar et al, 2009), kinetic spectrophotometry (Niazi et al, 2008), extractive spectrophotometry (Kanetake and Otomo, 1988;Reddy et al, 2008;Safavi et al, 1997;Davis, 1969) and spectrophotometry (Mori et al, 1999;Marczenki and Kus, 1985;Otomo, 1963;Horiuchi and Nishida, 1967;Mizuno and Miyatani, 1976;Marczenki, 1986).…”

“…The determination of trace amounts of Pd in environmental samples required a preconcentration/separation procedure when relying on the reported methods (Cetin et al, 2013;Tillery and Johnson, 1975;Tokalioglu et al, 2004;Chwastowska et al, 2004;Rojas et al, 2006;Liang et al, 2009;Moldovan et al, 2003;Dias and Nozaki, 1998;Dong et al, 2006;Vojkovic and Druskovic, 2003;Kumar et al, 2009;Niazi et al, 2008;Kanetake and Otomo, 1988;Reddy et al, 2008;Safavi et al, 1997;Davis, 1969;Mori et al, 1999;Marczenki and Kus, 1985;Otomo, 1963;Horiuchi and Nishida, 1967;Mizuno and Miyatani, 1976;Marczenki, 1986), because of their very complex sample matrices. Conventional extractive spectrophotometric procedures for preconcentration and separation, although effective, are tedious, time-consuming, require large amount of sample and reagents and sometimes vulnerable to contamination and losses of analyte.…”

Determination of Traces of Pd(II) in Spiked Samples by Using 3,4-Dihydroxybenzaldehydeisonicotinol-hydrazone as a Chelating Agent with UV Visible Spectrophotometer

“…Environmental contamination by the platinum group element (PGEs), mainly related to automotive catalytic converters, is exponentially increasing and reliable and accurate quantification is a mandatory task. The wide use of palladium not only in automotive catalytic converters but also as a drug and in food production has led to a more uncontrolled release of those metals in the environment 2 . Palladium is one of the precious metals.…”