Tune solution

The initial aim is to optimize the system in order to obtain the maximum signal for a given concentration of analyte. A typical tuning solution comprises Be, Mg, Co, In, Ba, Pb and U at a concentration of 10 ng mbf... 

In ICP-MS a multi-element tuning solution is applied for the mass calibration of mass spectra. Figure 6.3 shows the mass spectrum for phosphorus determination at m/z = 31. In this case, the mass calibration was performed with the aid of a solution of a phos-phorus/sulphur mixture. From the known masses of the isotopes of the atomic ions, the masses of the polyatomic ions occurring were determined and identified in accordance with the isobaric polyatomic ions (15N160+ and 14N16OH+). Mass accuracy is the deviation of experimental determined mass of an atomic, polyatomic, cluster, molecular or fragment ion from the exact mass of species expected. Polyatomic, cluster and molecular ions were calculated from the atomic masses (see Appendix I), the mass accuracy is usually presented in ppm. 

H02 Hoogenboom, R., Thijs, H.M.L., Wouters, D., Hoeppener, S., and Sehubert, LF.S., Tuning solution polymer properties by binary water-ethanol solvent mixtures. Soft Matter, 4, 103, 2008. 

For multi-analyte method development, it is possible to use one tuning solution containing several different compounds for MRM optimization. However, there is always a possibility that impurities in any of the reference standards being used could result in the optimization being done for some solute other than the anal5h e of interest. For this reason it is safer to use independent timing solutions for the initial optimization of Qj and especially for product ion optimization. 

Methods to determine co-crystal solubility are based on thermodynamic and kinetic approaches. Thermodynamic equilibrium experiments provide a measure of co-crystal solubilization processes, while kinetic studies provide insight about the time scales of dynamic processes and concentration fluctuations during co-crystal dissolution. From equilibrium measurements, we can extract information about the origin of co-crystal solution phase behavior and fine tune solution processes by controlling thermodynamic solubility. We can use the knowledge gained from equilibrium studies to design kinetic studies and separate the thermodynamic and kinetic contributions to the co-crystal dissolution and transformation behavior. 

The instrument performance must be validated prior to the sample run according to the 200.8 method. This includes a 30 min instrument warm-up, mass calibration, peak resolution and stability check using the tuning solution (a multi-element mix spanning the mass range, e.g. Be, Mg, Co, Y, In, Ba, Tb, Pb, U). Peak scanning of 25,26]yjg 206,207,208p j verify... 

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