Uranium emission spectra with a low power microwave plasma source

Electron impact excitation-cavity ringdown absorption spectrometry of elemental mercury at 405 nm

“…Given the 0.75 ml per minute pumping rate of the sample solution into the ultrasonic nebulizer (a 10% nebulizer efficiency) and the known sample introduction gas flow rate, the total Hg number density generated in the plasma can be estimated. Using the same estimation method as reported elsewhere, 2,12,13,16 the total Hg number density in the plasma was 3.75 Â 10 11 atoms cm À3 . The estimated total Hg number densities in the plasma for other sample solutions are also listed in Table 1.…”

“…Detection sensitivities range from pg ml À1 to ng ml À1 (1 pg ¼ 10 À12 g, 1 ng ¼ 10 À9 g). 1,2,[10][11][12][13][14][15][16] Although improving the detection sensitivity of the plasma-CRDS technique is still under study, one challenging issue that needs to be addressed is the instrumental portability of the plasma-CRDS-based spectrometers. Currently no single portable plasma-CRDS spectrometer has been reported, mainly due to the high cost and bulky geometry of the laser source, since a compact, low-cost plasma source has recently become available.…”

Plasma-cavity ringdown spectroscopy (P-CRDS) for elemental and isotopic measurements

“…In one reported experiment, a three coaxial brass torch powered by a 2450 MHz microwave power supply was used as the plasma source to generate a candle-shaped plasma operating at 100-150 W. 82 Very recently, a tube-shaped MIP, utilizing quartz tubing with inner diameters of 2-5 mm to house the plasma, has been employed as the plasma source and examined with CRDS. This type of compact plasma can operate at as low as 15 W. 75,119,139 The tube-shaped torch not only efficiently operates at significantly lower operating powers, but also offers a longer laser beam path-length in the plasma, which is favorable for absorption measurements. Table 1 lists typical operating parameters for the different plasmas used in the P-CRDS systems mentioned above.…”

“…Interestingly, a recent work has demonstrated that an MIP operating at 150-180 W effectively generates U atoms and ions. 139 This characteristic is attributed to the high excitation efficiency of the spatially-confined MIP plasma plume. For the tube-shaped MIP, the plasma power was only about 50-80 W. 119 This miniature plasma was found to effectively generate a variety of elements, including Hg and Pb.…”

Atomic spectrometry update. Advances in atomic emission, absorption and fluorescence spectrometry, and related techniques

“…265 A 200 W microwave plasma, operated with an argon gas flow of B1 l min À1 , has been used to obtain uranium emission spectra in the 320-430 nm region. 266 Both T rot and T vib were calculated to be 2800 K.…”