Determination of platinum in biotic and environmental materials part II: A sensitive voltammetric method

Platinum(II), Palladium(II), Rhodium(III) and Lead(II) Voltammetric Determination in Sites Differently Influenced by Vehicle Traffic

The present work reports analytical results relevant to voltammetric determination of Pt(II), Pd(II), Rh(III) [Platinum Group Metals (PGMs)] and Pb(II) in superficial water sampled in sites differently influenced by vehicle traffic, especially considering their temporal behaviour. For all the elements, in addition to detection limits, precision, expressed as relative standard deviation (s(r) %) and accuracy, expressed as percentage recovery (R %) are also reported. In all cases they show to be good, being the former lower than 6% and the latter in the range 94-105%. A critical comparison with spectroscopic measurements is also discussed.

Determination of platinum-group metals and lead in vegetable environmental bio-monitors by voltammetric and spectroscopic techniques: critical comparison

This paper reports voltammetric sequential determination of Pt(II), Pd(II), and Rh(III), by square-wave adsorption stripping voltammetry (SWAdSV), and Pb(II), by square-wave anodic stripping voltammetry (SWASV), in vegetable environmental matrices. Analytical procedures were verified by the analysis of the standard reference materials: Olive Leaves BCR-CRM 062 and Tomato Leaves NIST-SRM 1573a. Precision and accuracy, expressed as relative standard deviation and relative error, respectively, were always less than 6% and the limits of detection (LOD) for each element were below 0.096 mug g(-1). Once set up on the standard reference materials, the analytical procedure was transferred and applied to laurel leaves sampled in proximity to a superhighway and in the Po river mouth area. A critical comparison with spectroscopic measurements is discussed.

Platinum group elements in the environment and their health risk

Accumulation of platinum group elements (PGEs) in the environment has been increased over the time. Catalytic converters of modern vehicles are considered to be the main sources of PGE pollution, since the correlation is between the Pt:Rh ratios in various environmental compartments and in converter units. The present literature survey shows that the concentration of these metals has increased significantly in the last decades in diverse environmental matrices; like airborne particulate matter, soil, roadside dust and vegetation, river, coastal and oceanic environment. Generally, PGEs are referred to behave in an inert manner and to be immobile. However, there is an evidence of spread and bioaccumulation of these elements in the environment. Platinum content of road dusts can be soluble, consequently, it enters the waters, sediments, soil and finally, the food chain. The effect of chronic occupational exposure to Pt compounds is well-documented, and certain Pt species are known to exhibit allergenic potential. However, the toxicity of biologically available anthropogenic Pt is not clear. Hence, there is a need to study the effect on human health of long-term chronic exposure to low levels of Pt compounds.

Platinum determination by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS) in different matrices relevant to human biomonitoring

The analytical challenges of Pt determination by ICP-SFMS posed by different human tissues and fluids have been critically assessed. Investigated samples were (1) urine, (2) serum of cancer patients sampled during chemotherapy with carboplatin, (3) microdialysates (20 micro L sample volume) collected from tumor and non-tumor tissue, and, finally-for the first time-(4) human lung tissue to study background concentrations of inhaled platinum. Sample preparation involved microwave digestion and open vessel treatment or simple dilution (microdialysates). Depending on the sample preparation and introduction systems used (microconcentric nebulization, ultrasonic nebulization with and without membrane desolvation) excellent procedural detection limits (3s criterion) of 0.35 pg g(-1) for urine, 420 pg g(-1) for serum, 400 pg g(-1) for lung tissue and 13 pg g(-1) for microdialysates could be obtained. Ultratrace concentrations of 1-40 pg g(-1), and 1000-3000 pg g(-1) were measured in urine and human lung tissue, respectively, as typical for samples in environmental studies. Quantification was carried out by IDMS and standard addition in the case of urine samples. Internal standardization could not correct for non-spectral interferences in external calibration. In the serum and microdialysates of patients during chemotherapy with carboplatin, elevated Pt levels ranging between 0.01 and 10 micro g g(-1) were determined by external calibration ((195)Pt isotope). For all investigated samples spectral interferences could be excluded by following different strategies. High-resolution control measurements ((194)Pt, (195)Pt) were performed in the case of elevated Pt levels, i.e. for microdialysates and serum samples. An Hf/Pt ratio of 0.4 was determined in human lung samples. An HfO formation ratio of 0.2% was assessed for standard solutions at the present experimental conditions, revealing that the contribution of (179)Hf(16)O, (178)Hf(17)O, (177)Hf(18)O to the (195)Pt isotope signal used for quantification was not significant.

Platinum uptake by the freshwater isopod Asellus aquaticus in urban rivers

Platinum has been increasing in the environment as a result of emissions from catalytic converters. The platinum emitted is principally located in the vicinity of roads but might be transported to urban rivers through highway and urban run-off water. Platinum concentrations in the freshwater isopod Asellus aquaticus were measured for two urban rivers and a stormwater detention pond. Concentrations ranged from 0.04 to 12.4 micrograms g-1 for direct analysis and from 0.16 to 4.5 micrograms g-1 after depuration. Analyses of water, pore water and sediments indicate that platinum in urban rivers is mostly found in the sediments and these provide the major contribution of platinum to Asellus aquaticus. Exposure experiments showed the importance of platinum speciation for uptake.

Determination of carboplatinum and cisplatinum by interfacing HPLC with ICP-MS using ultrasonic nebulisation

A novel HPLC technique has been developed for the determination of carboplatinum(II) and cisplatinum(II) which are used for chemotherapy. The compounds were separated by a HPLC column. The eluent was on-line nebulized into the nebuliser gas flow using ultrasonic nebulisation. The resulting aerosol was driven by the nebuliser gas stream through a 30-cm heating path, a 60-cm cooling path for desolvatisation and into the plasma of the ICP-MS. The detection was carried out on platinum mass 195Pt. Different RP C18 techniques were tested to obtain the best separation and detection results of the two platinum compounds. The solvent-generated anion exchanger method was selected as the method with the best handling and sensitivity. This technique allows a good separation of the two compounds within 3 min. The detection limits for carboplatinum and cisplatinum were 130 and 80 pg, respectively. The newly developed system has been applied to study the behaviour of the platinum species under different anion influences in aqueous solutions. These investigations are necessary for the future development of an extraction from environmental samples for the two compounds. In further experiments the distribution of the two platinum species, Na2Pt(II)Cl4 and the palladium species. Na2Pd(II)Cl4 between water/sediment, water/charcoal, sewage sludge/water and the distribution in the solution after iron flocculation were investigated to plan an extraction method for the platinum species from environmental matrices.

Urinary platinum in hospital personnel occupationally exposed to platinum-containing antineoplastic drugs

Urinary platinum levels of 21 nurses and hospital pharmacy personnel occupationally exposed to platinum containing antineoplastic drugs were determined in 24-h urine by voltammetric analysis after UV photolysis. All study participants applied standard safety measures, including a vertical laminar air-flow cabinet and latex gloves. The amount of platinum-containing drugs prepared for intravenous application ranged from 40-3260 mg/day. Urinary platinum was detected in 9 of 52 urine samples collected on days when platinum-containing drugs were mixed (limit of determination 4 ng/l). In comparison with a non-exposed control group, elevated urinary platinum levels were found in one pharmacist (35 ng/g creatinine) and one pharmacy technician (28 ng/g creatinine). The pharmacist's urinary platinum remained elevated after 2 days without occupational exposure to antineoplastic drugs. The urinary platinum level of the pharmacy technician dropped considerably after several weeks without handling cytostatic drugs. Voltammetric detection of urinary platinum is a highly sensitive method suitable for biological and environmental monitoring.