Yttrium internal standard

Urine No sample preparation other than addition of yttrium internal standard ICP-AES 12 pg/L 77% at 13 pg/L Kimberly and Paschal 1985... 

Apparatus Use a suitable Inductively Coupled Plasma Emission Spectrophotometer set to 226.502 nm for cadmium and to 371.029 for yttrium (internal standard) with an axial view mode. (This method was developed using a Perkin-Elmer Model 3300 DV equipped with a sapphire injector, low-flow GemCone nebulizer, cyclonic spray chamber, and yttrium internal standard.) Use acid-rinsed plastic volumetric flasks and other labware. 

Procedure Set up the instrumental method to measure the area of the 0- ig/mL Working Calibration Standard (blank) peaks and then the net intensities of the 0.050- and 0.250-fig/ mL Working Calibration Standards with the yttrium Internal Standard. The calibration curve should be linear. Examine the spectra of the cadmium and yttrium, and make any necessary adjustments to the exact peak locations and baselines to ensure proper integration of the areas under the respective peaks. Analyze the sample and calculate the concentration, in micrograms per milliliter, of the cadmium in the Sample Solution. 

Sample A is centrifuged at 2500 rpm for 20 min and approximately lO.Og of the top clear layer is accurately weighed into a 100 ml plastic volumetric flask. The centrifuged oil is dissolved in tetralin solvent with 10.0 ppm yttrium internal standard added and made up to mark with tetralin solvent. 

Analysis. Multi-element calibration standards of 0.0, 5.0 and 10.0 ppm Fe, Ca, B, Cu and A1 are prepared by dissolving 0.5 and 1.0 ml of 1000 ppm multi-element standard control stock in tetralin solvent to 100 ml with the same concentration yttrium internal standard as for samples A and B. Both samples are stirred and nebulised to determine the metal content against a standard calibration curve and corrected with an internal standard using ICP-OES. 

In addition to meeting the foregoing requirements, a good internal standard will be easy to add uniformly and precisely, and (preferably) no appreciable amount of the element St (free or combined) will be present in the sample before the addition. Cope29 provides an excellent illustration of these points. He found that yttrium nitrate dissolved in ethyl alcohol could be added to a powdered uranium mineral in a mortar, whereupon grinding immediately to dryness dispersed the internal standard (yttrium) so uniformly that uranium could be satisfactorily determined in certain minerals. But the mineral euxenite is an exception, for it contains both yttrium and uranium, and this complicates the uranium determination with yttrium as internal standard. 

Group IY is by all odds the most diverse and the most interesting of the four categories. Because the matrix is variable and often unknown, an internal standard is almost obligatory for all but the crudest exploratory work. The determination of uranium by use of yttrium (Cope, 7.12) and the determination of molybdenum with tungsten as a built-in standard (7.14) belong in Group IV. 

Yttrium, as internal standard in x-ray emission spectrography of uranium, 187, 203... 

ICP-AES was validated for the simultaneous determination of Al, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Pb, Se, Sr and Zn in human serum in a clinical laboratory. The samples underwent digestion and yttrium was used as an internal standard. The LOD were as follows 0.002-0.003 (xM for Ba, Cd, Mn and Sr 0.014-0.07 (xM for Be, Co, Cr, Cu, Fe, Li, Ni, Pb and Zn and 0.2-0.9 (xM for Al, B and Se. The concentrations of Al, Be and Co in human serum were found to be above the LOD, while those of Cd, Cr, Ni and Pb were below the LOQ however, in case of acute intoxication with the latter elements the method is valid . Matrix effects were evaluated for ICP-AES analysis using solution nebulization and laser ablation (LA) techniques. The main matrix-related interferences stem from elements with a low second ionization potential however, these are drastically reduced when pure He is used as carrier gas. This points to Ar (the usual carrier) participation in the interference mechanism, probably by interacting with doubly charged species. ... 

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. 

The standard addition calibration mode was adopted for all determinations since matrix effects were found to be significant, as expected for complex samples as those under test. Yttrium was used as the internal standard at the concentration of 100 ng g-1 for ICP-AES and Rh at the concentration of 5 ng g-1 for both Q-ICP-MS and SF-ICP-MS. The accuracy of the whole procedure was tested using the CRM NIST SRM 1568a Rice Flour, as set out in Table 12.1. 

Procedure Notes Some sample types may naturally contain significant levels of yttrium. In these cases, choose a suitable alternative internal standard, or mn the test without an internal standard. Use of the internal standard is not required, but it is helpful when there are variations in the viscosity among sample types. Samples may be prepared in higher or lower concentrations as needed. Standard concentrations may be adjusted as needed. Alternative procedures should be validated before use. 

Sample Solutions. The urine sample solutions all originated from one composite urine sample. The latter was made by combining 150-mL aliquots of the entire first-morning voids of 16, presumably healthy, male subjects. Aliquots of the composite were used to prepare three sets of sample solutions as indicated in Table IV. The solutions in each set were "spiked with internal reference elements and with appropriate volumes of multielement stock solution to make a (multiple) standard addition series (12). The final gallium and yttrium internal reference-element concentrations were 1.0 and 0.1 mg/L, respectively, for both the reference and standard addition solutions. The added analyte concentrations for both the reference and standard addition solutions were 0, 2, 4, 10, and 20 times the approximate "normal analyte concentrations for urine, as listed in Table II. 

Standard Calibration Curve with Internal Standard Method. The above experiments were repeated using samples prepared in Table 5.7 and include yttrium (Y) as an internal standard. The Y internal standard (obtained dissolved in oil available from MBH Conostan) was added to each sample and standard at a concentration equal to the highest concentration of metal, i.e. 10.0 ppm. The internal standard can be used to quantify each of the metals in each solution. 

The element yttrium was selected as internal standard because of its rare presence in crude oils and it behaves similarly in terms of atomisation efficiency to most elements present in cmde oils. 

Table 5.19 Results of analysis of wear oil obtained from a local automobile factory using a slurry method and yttrium as internal standard. The results before and after centrifugations are indicative of suspended and dissolved metal content...

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. 

ISO (1999) Draft international Standard Determination of platinum in platinum jewelry alloys -Method using inductively coupled plasma emission spectrometry on a solution with yttrium as internal standard ISO/DIS 11494.2 ISO/TC 174. 

An internal standard is often Used in emission spectrometry. In thi.s case, the vertical axis of the calibration curve i.s Ihe ratio or the log ratio of the detector signal for the analyte to the deiccfor signal for Ihe internal standard. Figure 10-16 shows calibration curves for several elements. In these experiments a lived amount of yttrium was incorporated in all of the sian-... 

FIGURE 10-16 Internal standard calibration curves with an tCP source. Here, an yttrium line at 242.2 nm served as an internal standard. NoUce the lack of interelement interference. (From V. A. Fassel. Science. 1978. 202,187. With permission Copyright 1978 by the American Association for the Advancement of Science.)... 

Samples were prepared by diluting 1.0 g of gasoline or diesel fuel with 99.0 g of kerosene containing Yttrium (Y) intern standard. 

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... 

An alternative way is given by the internal standard method, in which a particular element (most often yttrium) is added in known quantity to the sample to be analyzed. Special care should be taken of homogeneous mixing during addition. In this method an absolute determination of the bombarding particle current is not essential, furthermore matrix effects are well accounted for. The use of thick multielemental standards offers a relatively fast and simple way. However, differences in the composition of standards and samples to be analyzed make matrix corrections necessary if improved accuracy is needed. 

Internal Standard—Oil-soluble cadmium, cobalt, or yttrium are required when the internal standardization option is selected. 

Internal Standard Solution—Weigh 20 g of 0.500 mass % cadmium, cobalt, or yttrium (or any other suitable metal) organometallic concentrate into a 1 L volumetric flask and dilute to 1 L with the dilution solvent. Prepare fresh, at least weekly, and transfer this solution into a dispensing vessel. The concentration of the internal standard element is not required to be 100 pig/mL however, the concentration of the internal standard element in the test specimen solution should be at least 100 times its detection limit. 

---