NewWave UP193

...means laser-ablation inductively coupled plasma mass spectrometry. We use a New Wave UP193 for the quantitative analysis of various types of solid samples.

How it works

Laser-ablation ICP-MS is a method for microchemical (spot) analyses of trace element concentrations and isotope ratios in solid materials. By firing a high-energy laser beam onto the sample surface, material is ablated and thus a hole "drilled" into the sample. The ablated microparticles are removed from the sample chamber by an argon or helium carrier gas, and the aerosol is directly introduced into the hot plasma of an ICP-MS to be analyzed. Elements in concentrations as low as 10 ppb (ng/g) can be analyzed and quantified. See examples

The laser

The UP193ss by NewWave is a solid state laser with a wavelength of 193 nm (deep ultraviolet), a pulse width of c. 3 ns, and an irradiance at the sample of up to 2 GW/cm2. The short wavelength minimizes elemental fractionation at the ablation site and allows for ablation even of colorless minerals such as calcite. Spot sizes can be selected from 10 to 100 microns and pulse rates from 1 to 10 Hz. Samples can be ablated using individual spots, lines/rasters of spots, and continuous lines/rasters. Samples can be illuminated by reflected (coax and ring) as well as transmitted light.

Sample types and preparation

Almost any type of solid sample can be analyzed. The samples do not need to be coated or vacuum-resistant. They also do not need to be polished, although this may facilitate sample inspection and point location. Petrographic thin sections can directly be analyzed, e.g. after electron microprobe analyses of major elements; in this case the coating should be removed. The materials analyzed in our lab so far include silicate and non-silicate minerals, glasses, volcanic glass shards, foraminifers, otoliths, statoliths, bivalve shells, and more.

The normal sample chamber has a diameter of c. 45 mm limiting the maximal sample size. Samples can be mounted and fixed in many ways. Ideally, samples are prepared on a standard 1-inch mount (25 mm diameter, 5...20 mm height), as petrographic thin sections (max. 28 x 48 mm), or as fragments of < 3 mm thickness (see figure).

Calibration and data reduction

For determination of elemental concentrations, one element with known concentration (internal standard) must be analyzed along with the elements of interest in both sample and calibration standard. This is often 43Ca or 29Si and must be determined either by electron microprobe or by stochiometric calculations. For calibration and data monitoring we use synthetic glasses doped with trace elements (NIST610, NIST612), synthetic glasses from natural rocks (MPI-DING glasses, Jochum et al. 2000; USGS glasses BCR2G, BIR1G and BHVO2G), pressed pellets from carbonates, and others. Data reduction is carried out using both GeoPro(TM) and Glitter(TM) software.

User regulations ICP-MS (only in German)