Quantification of trace metalloids and metals in airborne particles applying dynamic reaction cell inductively coupled plasma mass spectrometry

Determination of trace contents of metals and metalloids, monitored in airborne particles for their adverse health and environmental impact or to discriminate pollutant particulate emission sources, requires very sensitive analytical methods. Dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS) has been applied to measure ultra-trace elements found in PM10 atmospheric particles in order to determine simultaneously, rapid and accurate concentrations for well known highly interfered isotopes (75As, 59Co, 52Cr, 53Cr, 58Ni, 60Ni, 78Se, 45Sc, and 51V). The challenge resides in the extremely low content of these elements encountered in PM10 particles, while thorough mineralization procedures in complex matrices are necessary to deal with refractory minerals. The potentially interfering polyatomic ions combining Ar, Cl, F, O, N, and C isotopes were significantly reduced by using NH3 as the reaction gas in the DRC, optimizing the reaction cell band pass and tuning of the gas flow rate. Standard Reference Material (NIST 1648) as well as real atmospheric samples were analyzed under the best defined conditions to validate and exemplify our methodology. The method detection limits are 450 ng/L for As, 13 ng/L for Co, 1210 ng/L for Cr, 780 ng/L for Ni, 47 ng/L for Se, 22 ng/L for Sc, and 26 ng/L for V. Based on real atmospheric sample measurements, DRC-ICP-MS associated with NH3 is confirmed as a cost effective technique to produce accurate results during routine working procedures for all these elements except Se.

Microwave digestion—ICP-MS for elemental analysis in ambient airborne fine particulate matter: Rare earth elements and validation using a filter borne fine particle certified reference material

NIST standard reference material SRM 2783 was employed to validate a high temperature, high pressure, two-stage microwave assisted acid digestion procedure using HNO3, HF and H3BO3 developed for the analysis of trace elements (including rare earths) in atmospheric fine particulate matter (PM2.5) prior to inductively coupled plasma mass spectrometry (ICP-MS). This method quantitatively solubilized Na, Mg, Al, K, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sb, Cd, Cs, Ba, Pb, Th, U and several rare earth elements (REEs) (La, Ce, Pr, Nd, Gd, Dy, Er, Sm and Eu) from SRM 1648 and SRM 2783. A small amount of HF in the first stage was required to dissolve silicates necessitating the corresponding addition of H3BO3 in second stage to dissolve fluoride precipitates of Mg, La, Ce and Th. The optimized microwave dissolution-ICP-MS method detected Na, Mg, Al, K, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Cd, Mo, Sb, Cs, Ba, La, Ce, Pr, Nd, Sm, Gd, Pb, Th and U at trace to ultra-trace levels in ambient airborne fine particles from three sites in North Carolina. La to light lanthanide signature ratios suggested that soil and motor vehicles are the dominant REE sources in SRM 2783 and PM2.5 samples collected during this study.

Square-wave stripping voltammetry for direct determination of eight heavy metals in soil and indoor-airborne particulate matter

The application of square-wave voltammetry (SWV) for the determination of eight elements viz. Cd(II), Pb(II), Cu(II), Zn(II), Co(II), Ni(II), Cr(VI), and Mo(VI) in soil and indoor-airborne particulate matter has been examined and optimized. The cathodic and anodic types of the SWV technique were examined for the detection of these metal ions. It was found that the square-wave anodic stripping voltammetry is the conventional technique for the determination of Zn(II), Cd(II), Pb(II), and Cu(II), but square-wave adsorptive cathodic stripping voltammetric method is used for the determination of Co(II), Ni(II), Mo(VI) and Cr(VI). Various experimental parameters, which influenced the response of the mercury film electrode to these metal ions, were optimized. The detection limits of these metal ions were 0.03, 0.4, 0.04, 0.1, 0.15, 0.05, 0.2, and 3.2 microg/kg for Cd(II), Pb(II), Cu(II), Zn(II), Co(II), Ni(II), Cr(VI), and Mo(VI), respectively, with very good accuracy (standard deviation is below 2%). Interference from coexisting ions was successfully investigated. A comparison of analytical data for analyzing real samples was carried out between the SWV method and the graphite furnace atomic absorption spectrophotometric (GFAAS) method. By the standard addition method, the recoveries were 96.6-104% with SD of 0.75-2.5%. The great advantage of SWV is the simplicity, selectivity, sensitivity, and shortening analysis time over the GFAAS method.

The homogeneity of heavy metal deposition on glass fibre filters collected using a high-volume sampler in the vicinity of an opencast chrome mine complex at Kemi, Northern Finland

The homogeneity of heavy metal (Cr, Ni, Cu, Fe and Cd) distribution on glass fibre filters (Munktell MG 160, 203 x 254 mm, 75 g m(-2)) collected using a high-volume sampler (Wedding & Associates) at an opencast chrome mine complex at Kemi, Northern Finland was studied. The heavy metals in the total suspended particulate (TSP) material were analysed by inductively coupled plasma atomic emission spectrometry (ICP-AES) or graphite furnace atomic absorption spectrometry (GFAAS). The glass fibre filters were digested in a microwave oven using a mixture of aqua regia+HF acids. There was significant non-uniform distribution of heavy metals on glass fibre filters. The TSP material containing chromite was very difficult to dissolve by acid digestion. The results from X-ray fluorescence spectrometry (XRF), and from energy filtering transmission electron microscope (EFTEM) equipped with energy dispersive X-ray spectrometer (EDS), showed that insoluble residue left after microwave oven digestion with aqua regia+HF acids was probably partly due to chemical reactions occurring during microwave heating.

Spectrophotometric determination of vanadium(V) in minerals, steels, soil and biological samples using phenothiazine derivatives

Two simple, rapid and sensitive spectrophotometric methods have been proposed for the determination of vanadium(V) using butaperazine dimaleate (BPD) and propionyl promazine phosphate (PPP). These methods are based on the formation of red-colored radical cations on reaction with vanadium(V) in phosphoric acid medium, with their absorbance maxima at 513 nm. Beer's law is valid over the concentration range of 0.25-5.0 micrograms ml-1 and 0.2-4.0 micrograms ml-1, with Sandell's sensitivity values of 6.1 ng cm-2 and 6.0 ng cm-2 for BPD and PPP respectively. The proposed methods have been successfully applied to the analysis of vanadium steels, minerals, biological samples and soil samples.

Upper airway response in workers exposed to fuel oil ash: nasal lavage analysis

OBJECTIVES

Among other constituents, fuel oil ash contains vanadium pentoxide, a known respiratory irritant. Exposure to ambient vanadium pentoxide dust has been shown to produce irritation of the eyes, nose, and throat. The usefulness of nasal lavage in detecting an inflammatory response to exposure to fuel oil ash among 37 boilermakers and utility workers was investigated.

METHODS

A baseline lavage was performed on the morning of the first day back to work after an average of 114 days away from work (range 36 hours to 1737 days). A lavage was performed after exposure on the morning three days after the baseline lavage. Exposure to respirable particulate matter of diameter < or = 10 microns (PM10) and respirable vanadium dust were estimated with daily work diaries and a personal sampling device for respirable particulates. These estimates were made for each subject on each workday during the three days between lavages. For each subject, the adjusted change in polymorphonuclear cells was calculated by dividing the change in polymorphonuclear cell counts by the average of the counts before and after exposure. The association between the adjusted polymorphonuclear cell counts and exposure was assessed with multiple linear regression, adjusted for age and current smoking.

RESULTS

Personal sampling (one to 10 hour time weighted average) showed a range of PM10 concentrations of 50 to 4510 micrograms/m3, and respirable vanadium dust concentration of 0.10 to 139 micrograms/m3. In smokers the adjusted polymorphonuclear cell count was not significantly different from zero (-0.1%, P > 0.5), but in nonsmokers it was significantly greater than zero (+50%, P < 0.05). In both non-smokers and smokers, there was considerable variability in adjusted polymorphonuclear cell counts and a dose-response relation between these adjusted cell counts and either PM10 or respirable vanadium dust exposure could not be found.

CONCLUSION

A significant increase in polymorphonuclear cells in non-smokers but not smokers was found. This suggests that in non-smokers, exposure to fuel oil ash is associated with upper airway inflammation manifested as increased polymorphonuclear cell counts. The lack of an increase in polymorphonuclear cells in smokers may reflect either a diminished inflammatory response or may indicate that smoking masks the effect of exposure to fuel oil ash.