Uncertainty of high resolution inductively coupled plasma mass spectrometry based aerosol measurements.

Simultaneous and multi-elemental method was optimized to determine 35 elements in 274 coarse and fine aerosol samples by using HR-ICP-MS. The procedures were validated. Measurement uncertainties of all elements including sampling uncertainties were calculated by applying bottom-up approach. The average recoveries obtained for each element ranged between 79% and 129% using NIST SRM 1648, urban dust. The calculated uncertainties of the analytical methods were between 2.9% and 18% for both sample types. The major contributions to the uncertainty budget come from the calibration curves, repeatability and volume of air.

Selenium speciation in dill (Anethum graveolens L.) by ion pairing reversed phase and cation exchange HPLC with ICP-MS detection.

In the present work, speciation of selenium in dill (Anethum graveolens L.), supplemented with sodium selenite during its growth, was performed using ion pairing reversed phase and cation exchange chromatography. Heptafluorobutyric acid (HFBA) was used as the ion-pairing agent in reversed phase chromatography. In cation exchange chromatography, two different gradient programs were employed for the identification of selenospecies using pyridinium formate as the mobile phase. Low molecular weight selenocompounds were extracted from root, stem and dill leaf with 0.1M HCl. Enzymatic digestion was used for the extraction of selenospecies related to high molecular weight compounds. The chromatograms obtained from different parts of the plant revealed major differences in the type of selenospecies as well as their concentrations. The major selenospecies found in different parts of the plant is Se-methyl-selenocysteine (MeSeCys). Another major Se species identified is Se-methyl-selenomethionine (MeSeMet), which has the highest relative concentration in the root indicating possible Se volatilization from that part of the plant. Selenomethionine (SeMet) is present in minor quantities in all parts of the plant.

Flow injection-hydride generation-infrared spectrophotometric determination of Pb.

A novel analytical technique has been suggested for determination of Pb using formation of PbH(4)(g) by chemical reduction and its subsequent spectrophotometric measurement in IR region, using the peak at 1821.4cm(-1). The range of measurements is 1.0-30.0mgl(-1) using a sample of 1.0ml in flow injection mode. The 3sigma limit of detection is 0.28mgl(-1). The method has been applied to standard reference materials of Waste Water, EU-L-1, lead-base bearing metal 53e and Soil/Sediment #4 as well as soil samples collected from heavy traffic areas in Ankara.