Combining pyrohydrolysis and ICP-MS for bromine and iodine determination in airborne particulate matter

In this work, a method based on pyrohydrolysis of airborne particulate matter (APM) collected on glass fiber filter and subsequent determination of bromine and iodine by inductively coupled plasma mass spectrometry (ICP-MS) was developed. Samples of APM collected on glass fiber filter were ground using an agate mortar, homogenized and placed on an alumina platform. Samples were mixed with solid V2O5 and introduced into the pyrohydrolysis system. The main operational conditions of pyrohydrolysis (absorbing solution, heating time, sample mass and use of an auxiliary reagent - V2O5) were evaluated. Using selected conditions, samples of APM collected on glass fiber filter (300 mg, including the glass fiber filter) were mixed with 900 mg of V2O5 and heated at 950 °C during 15 min in a quartz tube under water vapor and air flow. The accuracy of the proposed method was evaluated by analyte recovery tests and also by analysis of certified reference material (CRM) with a similar matrix composition (NIST 2709 and NIST 1633b). Results were in agreement better than 104 and 95% for bromine and iodine, respectively, with CRM values. The limits of quantification (LOQs) of bromine (0.05 μg g− 1) and iodine (0.006 μg g− 1) were considered appropriate for APM analysis. The pyrohydrolysis sample preparation method was considered as relatively suitable to be performed in routine analysis and provides a clean solution for analysis by ICP-MS, which is very attractive for bromine and iodine determination in APM samples.