Scandium internal standard

An alternative to MSA in ICP-MS analysis is the internal standard technique. One or more elements not present in the samples and verified not to cause an interelement spectral interference are added to the digested samples, standards, and blanks. Yttrium, scandium, and other rarely occurring elements or isotopes are used for this purpose. Their response serves as an internal standard for correcting the target analyte response in the calibration standards and for target analyte quantitation in the samples. This technique is very useful in overcoming matrix interferences, especially in high solids matrices. 

Tris[bis(trimethylsilyl)amido]scandium(III) crystallizes from pentane as white, fragile needles, very sensitive to moisture, mp 172-174° (sealed tube). The proton NMR spectrum of a 10% solution in benzene, (TMS as internal standard) gives a single sharp resonance at r 9.66 and the mass spectrum shows a parent molecular ion corresponding to the three-coordinate monomer. Some infrared and electronic absorption spectra are given in Table II. The single-crystal X-ray... 

Figure 7.13 Calibration curves for boron, tungsten and molybdenum from 0.0 to 4.0gg/ml (ppm) using scandium Sc as an internal standard. The units on the Y axis are flask numbers of standards 0.0, 1.0, 2.0, 3.0 4.0 ppm metal respectively...

Table 7.5 Results of analysis of effects of low viscosity lubricating oil (Conostan 20) spiked with and without enhancing agents for the analysis of 0.5 (igmC1 of each metal against standard calibration curves, similar to Figure 7.13. All analyses were carried out using scandium as internal standard. Nl, no increase in signal...

Electrolytic solutions used for extra-renal infusion and dialysis contain metal chlorides of Na, K, Ca and Mg salts at concentrations that are critical for effective treatment. These solutions also contain dextrose, citrate and lactate additives as part of this special formulation. The analysis for these metals must be precise and accurate and this can be achieved with ICP-OES using yttrium or scandium as internal standard to correct for matrix affects. The method of standard addition may also be used with similar success but is a more tedious method. The ability to dilute the sample several fold due to the high concentrations of metals reduces/eliminates the effect of EIE (easily ionised elements) caused by other elements in the same solution. The dilution and the ease of detection and corrections with an internal standard using the multi-element capability make this an excellent method. 

Inductively coupled plasma atomic emission spectrometry (ICP-AES) was used for the determination of most major and trace elements. The samples are fused in a Claisse semi-automatic fusion device in Pt-Au crucibles with lithium metaborate (4). The fusion product is dissolved in diluted HNO and brought to volume. For trace elements determination the sample is decomposed by HF, HNOg and HCIO. Scandium serves as an internal standard and is added to all samples and solutions. The instrument (product of Jobin Yvon, France)is calibrated using multi-element synthetic standards. The aqueous solutions are nebulized and injected into the heart of a plasma fire ball. A computerized multi-channel vacuum spectrometer has been programmed for multi-element analysis. 

Today, ICP-MS permits very low detection limits (0.1 jgkg ) of tin in biological matrices. Sample preparation consists of reconstitution of the freeze-dried material or in microwave digestion, both followed by dilution in a solution of an internal standard (europium, indium, scandium, etc.) The main characteristic isotopes used for the determination of tin are Sn, Sn, Sn, and Sn. 

Elements which are not a constituent of the sample under analysis (e.g. scandium or yttrium) are particularly suited for use as the internal standard. Should it be the case that the element chosen as internal standard is in fact a constituent of the sample under analysis, the concentration of mass added to the sample under analysis should be approximately three... 

Water (1.51) was brought in a storage vessel and 200 pg of each of scandium and samarium were added as nitrate solution to serve as internal standards. The sample was then irradiated with 30 MeV bremsstrah-lung (mean electron beam current 150 pA) from an electron linear accelerator for 5h in a 0.7-1 flow-chamber under slow continuous cyclic flow. Thereafter, the components of interest (Sc, Cr, Mn, Co, Ni, Cu, Zn, As, Y, Zr, Nb, Mo, Cd, Sn, Sb, I, Ba, Tl, Pb, and U) were separated by a sulfur-substituted cellulose-based sorbant filter switched into the flow cycle after activation. This sorbant was then dried in a microwave furnace and pressed to a thin (1mm thick) pellet. Product activities were counted with a large coaxial germanium detector (where was... 

In the case of ICP-OES measurements scandium and/or beryllium is used as an internal standard. Differences in element concentrations in the plant digests can affect the nebuliser and/or the plasma conditions. Therefore scandium and/or beryllium will be nebulised in the plasma together with the sample. By measuring also scandium or beryllium a correction can made for all measured elements since the measured scandium or beryllium concentration should be constant. 

Scandium (5 mg/L), al a wavelength of 255.235 nm. is used in the author s laboratory as an internal standard to compensate for matrix effects. 

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