Parahydrogen hyperpolarization of minimally altered urine samples for sensitivity enhanced NMR metabolomics.

Parahydrogen hyperpolarization has been shown to enhance NMR sensitivity in urine analysis by several orders of magnitude if urine samples are prepared by solid phase extraction (SPE). We present a different approach, developed for minimal sample alteration before analysis. Removing SPE from the workflow allows to retain a wider range of metabolites and paves the way towards more universal hyperpolarized NMR metabolomics of low abundance metabolites.

The effects of iridium on the renal function of female Wistar rats.

Despite the widespread use of iridium (Ir) in catalytic converters for improved capacity for reducing carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NO(x)) emissions, there is a lack of studies that have assessed possible toxicological hazards of exposure to Ir. The present investigation indicates that female Wistar rats exposed to Ir in the drinking water for 90 days displayed renal toxicity based on the elevated urinary retinol binding protein (RBP) and albumin. The RBP was more sensitive to albumin, showing significant increases at 0.01 mg/L.

Environmental and biological monitoring of iridium in the city of Rome.

The use of iridium in the latest catalytic converters to further reduce nitrogen oxide emission in the exhaust of lean-burn engines could result in increased atmospheric levels of this element in high-density vehicle traffic areas. The objective of this study is to assess environmental Ir pollution and its urinary levels in workers and an urban control group. Environmental monitoring inside a tram consisted in air samplings of total suspended particles (TSP), PM10 and PM2.5 carried out during November 2005. Urinary Ir levels were evaluated in 64 municipal tram drivers and in 58 administrative employees as controls. Quantification of Ir in air samples and urine was performed by means of Sector Field Inductively Coupled Plasma Mass Spectrometry. Means+/-standard deviation of Ir levels in TSP, in PM10 and PM2.5 fractions were 1.43+/-1.66, 0.44+/-0.27 and 0.36+/-0.19 pg m(-3), respectively. No statistically significant differences were observed among urinary Ir values in the exposed subjects and control group. The Ir levels in Rome air are still sufficiently low, even if the increased use of new Ir-based catalysts could be of some concern in the near future. The results of our study are of interest as they are a first attempt to explore airborne levels and urinary concentrations of Ir in an urban context at medium-high density of vehicle traffic. Particular attention should be given to the fact that Ir was found in the finest dust particles as the effects of fine particles containing Ir have not yet been studied.

[Biomonitoring of iridium in a urban population]. / Biomonitoraggio dell'iridio in una popolazione urbana.

Iridium (Ir) is one of the six elements collectively known as the platinum group metals. For its excellent catalytic properties, Ir was recently introduced into DeNOx, a new generation of automotive catalysts. The aim of our study was to evaluate urinary Ir levels in an urban population. A total of 122 healthy male subjects of Rome (Italy) were studied. Ir quantification in the urine samples of these subjects was carried out by sector field inductively coupled plasma mass spectrometry. The mean urinary Ir level was 10.41 ng/g creatinine (standard deviation: 9.67; 25th-75th percentile: 3,62-12,74 ng/g creatinine). The scientific community should respond to a potential increase in environmental exposure to Ir, due to its growing use as a catalyst, with very careful evaluation of the biological levels of this metal and monitoring of airborne particulate present in the life environment. Further investigation will enable researchers to confirm and integrate the findings of our present study undertaken in the context of surveillance.