Asep Yoyo Wardaya

Rapid identification of elements in liquid by using pulse carbon dioxide laser-induced plasma spectroscopy

Identification of major elements in milk liquid has been rapidly carried out by using pulse carbon dioxide (CO2) laser. Experimentally, a milk liquid was poured on a Cu metal plate to make a thin film on the metal surface. The liquid was then dried at 100°C for 5 minute. A thin film of milk liquid was produced with a thickness of around 0.1 mm. The Cu plate only functions as a metal subtarget. A pulse CO2 laser was irradiated on a metal surface to induce a luminous plasma. The atomization of liquid and excitation processes of atoms from the film sample happen in the plasma region. Various major elements in milk liquid, namely Ca, Mg, Na, and K can successfully be detected. Therefore, the method has high-prospect for major elemental analysis in liquid sample target.Identification of major elements in milk liquid has been rapidly carried out by using pulse carbon dioxide (CO2) laser. Experimentally, a milk liquid was poured on a Cu metal plate to make a thin film on the metal surface. The liquid was then dried at 100°C for 5 minute. A thin film of milk liquid was produced with a thickness of around 0.1 mm. The Cu plate only functions as a metal subtarget. A pulse CO2 laser was irradiated on a metal surface to induce a luminous plasma. The atomization of liquid and excitation processes of atoms from the film sample happen in the plasma region. Various major elements in milk liquid, namely Ca, Mg, Na, and K can successfully be detected. Therefore, the method has high-prospect for major elemental analysis in liquid sample target.

Rapid Detection of Oil Pollution in Soil by Using Laser-Induced Breakdown Spectroscopy

Detection of oil pollution in soil has been carried out using laser-induced breakdown spectroscopy (LIBS). A pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (1,064 nm, 8 ns, 200 mJ) was focused onto pelletized soil samples. Emission spectra were obtained from oil-contaminated soil and clean soil. The contaminated soil had almost the same spectrum profile as the clean soil and contained the same major and minor elements. However, a C–H molecular band was clearly detected in the oil-contaminated soil, while no C–H band was detected in the clean soil. Linear calibration curve of the C–H molecular band was successfully made by using a soil sample containing various concentrations of oil. The limit of detection of the C–H band in the soil sample was 0.001 mL/g. Furthermore, the emission spectrum of the contaminated soil clearly displayed titanium (Ti) lines, which were not detected in the clean soil. The existence of the C–H band and Ti lines in oil-contaminated soil can be used to clearly distinguish contaminated soil from clean soil. For comparison, the emission spectra of contaminated and clean soil were also obtained using scanning electron microscope-energy dispersive X-ray (SEM/EDX) spectroscopy, showing that the spectra obtained using LIBS are much better than using SEM/EDX, as indicated by the signal to noise ratio (S/N ratio).