Prodigy high dispersion icp

Following the biosurfactant treatments, the physicochemical properties of the spent HDS catalyst were analyzed including pore volume, surface area, metal content, and coke content. ICP spectrometer (Teledyne-Leeman Labs-Prodigy-High Dispersion ICP) was used to measure the concentration of different metals (Mo, V, Ni) in the spent catalyst. This method involves atomizing the sample in a high-temperature plasma and resolving the atomic spectra into the lines of each element by optical grading in an optical spectrometer. The surface area of the spent HDS catalyst was determined by the Brunauer-Emmet-Teller (BET) method using Tri-Star surface area analyzer (Micrometrics Corporation). The nitrogen adsorption-desorption measurements for specific surface area (SSA) and total pore volume (TPV) were carried out at -196ºC (liquid nitrogen) in the relative pressure (P/P0) range of 0.05 to 0.3 with BET method.
Carbon loss was measured by loss on ignition (LOI) in presence of air, determination of volatile matter, and carbon oxidation behavior of the catalyst. Typically, about 100 mg of sample is heated from ambient to 650ºC at the rate of 4ºC per minute in air using normal furnace for decoking.

The sand samples were air-dried and ground to get a uniform grain size of 2 mm. Analysis of both sand and plant samples were carried out in the Charles Renard Analytical Laboratory (CRAL) at ICRISAT, Patancheru. The total nitrogen was analyzed adopting the thio-sulfate modification of the Kjeldahl method to include nitrate and nitrite ( Sahrawat et al. 2002a ). The plant samples (or sweet corn) were dried in an oven at 65 C for 48 h. The dried plant (or sweet corn) samples were then ground using an industrialgrade grinder (Willey, Nebraska, USA) to a fine powder. Total nitrogen in plant materials was determined by digesting the samples with sulfuric acid-selenium. Nitrogen in the digests was analyzed using an auto-analyzer (Skalar SAN System, AA Breda, Netherlands) (Sahrawat et al. 2002b) . The concentrations of trace metals in the plant samples as well as in the samples were determined by inductively coupled plasma emission spectrophotometer (ICP-AES) (Prodigy High Dispersion ICP, Teledyne Leeman Labs, Hudson, New Hampshire, USA) in the digests prepared by digesting the samples with nitric acid.