Adding colour to mass spectra: Charge Determination Analysis (CHARDA) assigns charge state to every ion peak

Traditionally, mass spectrometry (MS) output is the ion abundance plotted versus ionic mass-to-charge ratio m/z. While employing only commercially available equipment, Charge Determination Analysis (CHARDA) adds a third dimension to MS, estimating for individual peaks their charge states z, starting from z=1, and colour-coding z in m/z spectra. CHARDA combines the analysis of ion signal decay rates in the time-domain data (transients) in Fourier transform (FT) MS with the interrogation of mass defects of biopolymers. Being applied to individual isotopic peaks in a complex protein tandem (MS/MS) dataset, CHARDA facilitates charge state deconvolution of large ionic species in crowded regions, estimating z even in the absence of isotopic distribution (e.g., for monoisotopic mass spectra). CHARDA is fast, robust and consistent with conventional FT MS and FT MS/MS data acquisition procedures. An effective charge state resolution Rz≥6 is obtained, with potential for further improvements.

Point Zero Charge Determination and Fluoride Adsorption on Natural Red Ash (Metal Oxide)

The PZC is essential parameter for the characterization of certain materials used for the treatment of organic or inorganic wastes in the environment, particularly from waste water and industrial sludge. Potentiometric titration and batch experimentation method was used to determine PZC value and type of adsorption isotherm behavior observed. Red ash is the natural metal oxides collected from the rift valley of Ethiopia which have PZC values of 3.35 for 0.5g, 1g and 1.5g adsorbent dose studied. On the adsorbent surface, monolayer and homogeneous adsorption process of fluoride observed. Therefore, based on the interest of the researcher and the adjustment of the pH of red ash solution might used for the treatment of ionic wastes.