Direct quantitative elemental analysis of food powder samples by low-pressure inductively coupled plasma spectrometry with laser ablation system
Department of Chemistry
- 원문 URL
Low-Pressure ICP was constructed using Laser ablation sampling and characterized by time-integrated spatially resolved spectrometry. The spatial emission intensity profiles depend on the position on the plasma because these reflected the excitation procedure of elements on the source, plasma characteristics such as electron number density, temperature, and ionization potential of elements. ). The temperatures were raging from about 6,600 K to 4,200 K depending on the location in plasma. The maximum temperature was appeared at 8 mm from the center of load coil. The maximum electron number density of 3.6*E14 cm-3, which is using iron (Fe) atom and ion lines, was observed at 8 mm plasma region from the center of load coil. When the analyte is passing through the core zone on the LP-ICP, which is similar with atmosphere plasma, the neutral line intensities (Zn (I)) are emitted first and are increasing to 20 mm where is low electron density. When the neutral line intensities are decreased after the maximum point, the ionic lines (Zn (II)) are drastically increased, and when zinc ion line is decreasing, atom line intensity is increasing again. The effects of gas environments (argon, argon-helium, argon-oxygen) and of pressure over the range 0.2 to 200 torr on low-pressure ICP were studied with the use of emission measurements. These factors greatly influenced the shape atomic and ionic emission profiles, the electron number density and excitation temperature on plasma. In generally, the size of core zone on the plasma was decreased with reducing pressures, but the emission intensities of atom and ion were increasing with decreasing the pressure of the system.