No abstract

No abstract

No abstract

An interlaboratory comparison was performed to evaluate the analytical methods for quantification of anhydrosugars - levoglucosan, mannosan, galactosan - and biosugars - arabitol, glucose and mannitol - in atmospheric aerosol. The performance of 10 laboratories in Italy currently involved in such analyses was investigated on twenty-six PM (particulate matter) ambient filters, three synthetic PM filters and three aqueous standard solutions. An acceptable interlaboratory variability was found, determined as the mean relative standard deviation (RSD%) of the results from the participating laboratories, with the mean RSD% values ranging from 25% to 46% and decreasing with increasing sugar concentration. The investigated methods show good accuracy, evaluated as the percentage error (ε%) related to mean values, since method biases ranged within ±20% for most of the analytes measured in the different laboratories. The detailed investigation (ANOVA analysis at p < 0.05) of the contribution of each laboratory to the total variability and the measurement accuracy shows that comparable results are generated by the different methods, despite the great diversity in terms of extraction conditions, chromatographic separation - more recent LC (liquid chromatography) and EC (exchange chromatography) methods compared to more widespread GC (gas chromatography) - and detection systems, namely PAD (pulsed amperometric detection) or mass spectrometry.

Formaldehyde (H−CHO) is a chemical compound extremely common in many industrial productions. However, in 2004, it was reclassified as carcinogenic (H350) and mutagenic (H341). Therefore, stringent limitations on emissions were implemented; among them, the lowest limit (3 mg/m3) was adopted by some Italian Local Competent Authorities. Up to now, no European-validated method for emission control was available, and for this reason, a specific working group (WG 40) has been created in the framework of the European Committee for Standardization Technical Committees 264 (CEN TC 264) to publish a qualified method for the quantification of Formaldehyde emissions from stationary sources (i.e., power stations, incinerators, petrochemicals, and industrial plants that uses combustion for their energetic purposes). Some preliminary trial tests were conducted to evaluate (1) the sampling protocol, and (2) the analytical technique. From a measurement perspective, two methods were selected: EPA 323—VDI 3862-6 and VDI 3862-2. Every new method prepared by CEN shall be verified before publication in the field and in real conditions to verify its metrological properties (i.e., precision, biases, reproducibility, and repeatability), costs and the training needs for involved personnel. With this aim, two measuring campaigns were conducted, and some important conclusions emerged concerning the H−CHO sampling procedure. Due to high water levels normally present, condensation during sampling is critical and can cause unpredictable errors; wet traps (impingers) give good responses. The sampling in pure water appeared unstable, but using an H2SO4 solution solved this issue, thus being recommended.