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The judicious use of cis-Pt as an intravenously administrable Pt(II) drug for chemotherapy requires the evaluation of its interactions with blood proteins. Therefore, the combined use of modern analytical chemical speciation and of analytical proteomics approaches to study these interactions is described here. The method involves incubation of cis-Pt with standard proteins and human serum samples. The separation of the proteins is conducted by liquid chromatography in an anion exchange column (Mono Q). Simultaneous molecular detection by UV absorption (280 nm) and elemental detection (195Pt) using inductively coupled plasma mass spectrometry (ICP-MS) are performed. Using this set-up, the effects of the incubation time as well as the drug concentration on cis-Pt interactions with transferrin, albumin and innmunoglobulin G were studied. In addition, the nature of interactions was also investigated by means of electrospray mass spectrometry (ESI-Q-TOF) of the intact protein. Transferrin and albumin showed different interactions, binding one and four cisplatin molecules, respectively. Also, some typical proteomic studies were initiated by tryptic digesting the transferrin and albumin cis-Pt complexes followed by capillary-LC-ICP-MS and ESI-Q-TOF parallel detection of the peptides obtained. The capLC-ICP-MS chromatogram provided clear evidence of Pt-containing peptides remaining after tryptic digestion.

In this work, silver migration from commercial food containers was evaluated according to European Regulation 10/2011. Several experimental parameters affected silver release: food simulant, temperature, exposition time and sampled bag area. Results demonstrated a significant silver nanoparticle (AgNP) migration into aqueous and acidic simulants. The amount of silver migrated increased with storage time and temperature although, in general, silver showed a low tendency to migrate into food simulants (17 ng/g). However, the food simulant did not seem to be a really outstanding variable for long term storage. AF4-ICP MS was used to confirm the presence of AgNPs in the simulants. The low limit of detection achieved (0.4 μg L-1) allowed the identification of AgNPs and their size characterisation (40-60 nm). Finally, scanning electron microscopy/energy-dispersive X-ray analysis suggested a possible transformation of the AgNPs detected in the extracts, due to association with other ligands, such as chlorine and sulphur, present in the original containers.

This study evaluated the feasibility of asymmetric flow field flow fractionation coupled with inductively coupled plasma mass spectrometry (AF4-ICP-MS) for separation, characterization and quantification of silver nanoparticles (AgNPs) in complex nutraceutical and beverage samples. For improved determination, different analysis conditions were proposed depending on the NP size, i.e. below 20nm and in the 20-60nm range. After optimization of the different experimental parameters affecting the AF4 separation process and the analyte detection, the proposed methods showed a wide dynamic linear range (i.e., in the 10-1000¿gL-1) and limits of detection below 28ngL-1. A previous probe ultrasonication for 90s (corresponding to 45 pulses of 2s) of the tested samples resulted in complete AgNPs disaggregation. As a result, a fast accurate determination was achieved (complete analysis was done in ca. 37min). The practicality of the proposed methodology for the intended determination was demonstrated by successful determination of the AgNPs present in a variety of nutraceuticals and a beverage at concentration levels in the 0.7-29.5×103¿gL-1 range. A good agreement was observed among these concentration data and those determined by more conventional sample preparation techniques, such as ultracentrifugation and acid digestion. Also, the estimated NP sizes using AF4 compared satisfactorily with those determined by image techniques, i.e. transmission electron microscopy (TEM). All together demonstrated the utility of this novel analytical methodology for the analysis of AgNPs of different size in complex matrices.

Inductively coupled plasma mass spectrometry (ICP-MS) can be applied to organic tissues obtained from experimental animals. Hearing loss does not correlate with the platinum (Pt) concentration found in the inner ear. Drug structure and affinity to inner ear proteins could explain ototoxicity caused by cisplatin.To analyse Pt affinity for brain and ear tissues (of similar embryologic origin) in the Wistar rat and clearance gradient after a single dose, and to correlate these findings with hearing changes.Thirty-two Wistar rats were intraperitoneally injected with cisplatin at a dose of 5 mg/kg. Animals were sacrificed after obtaining auditory brain responses (ABRs) at 3, 7, 30 and 90 days (nine, seven, seven and nine animals, respectively). Brain and both temporal bones were extracted from each animal and analysed by ICP-MS to determine the absolute concentrations of the metal. Eight non-treated animals were employed as a control group.The ABR thresholds were significantly elevated in animals from all groups after cisplatin treatment. A maximum accumulation of Pt for inner ear and brain was revealed around the first week: 3.175 (57%) and 0.342 (72%), respectively. Pt significantly accumulated in greater quantities in ear than in brain (p0.01) and was cleared at a higher rate in brain than in ear (p0.01) following cochlea/brain ratio analysis. No statistically significant correlation was found between amounts of Pt and hearing loss in the study animals.

Flow injection systems incorporating microcolumns of Amberlyst A-26 and sulfhydryl cotton were combined with inductively coupled plasma atomic emission spectrometry for on-line preconcentration and determination of gold in waters. Use of a sampling volume of 10 ml and an eluent volume of 250 µl resulted in preconcentration factors of 40 and 50 with Amberlyst A-26 (eluent, ammonia solution) and sulfhyrdyl cotton (eluent, potassium cyanide solution), respectively. The limit of detection was about 1 µg l–1(for both microcolumns) and the precision was 1.2–3.5% at the 50 µg l–1 level. Application to the determination of gold in refinery effluent was demonstrated.