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When manual volumetric methods of preparing solutions are employed, variations of solvent density with temperature can lead to errors larger than the error inherent in the subsequent analytical procedure. In the PolyVISC SPS Solution Preparation System, the solvent is weighed rather than measured volumetrically, eliminating errors due to variations in solvent density. For samples over 100 mL, concentration accuracy is often better than ± 0.02 percent. When solutions are prepared using the gravimetric method, the solution concentration can be expressed in units of volume when the density of the solvent is known. Thus, it is possible for the PolyVISC SPS Solution Preparation System to prepare solutions for procedures written for the volumetric method. PolyVISC SPS components A computer-controlled burette pump and proprietary PolyVISC SPS software are at the heart of the Solvent Preparation System. The software permits convenient user configuration of multiple sample/solvent recipes. Other required system components (ordered separately) include a Windows-compatible computer and an electronic balance. A number of digital electronic balances having an RS-232 (COM) output are compatible with the SPS software package. Solution Preparation SPS software for Windows® makes solution preparation rapid and simple. No volumetric glassware is used*. After the sample ID information is entered, and the user-configured recipe is selected, the operator places an empty container on the balance pan. The container is weighed and the operator adds the amount of solute specified by the computer to the sample container. The precise solute weight is obtained; then the computer calculates the appropriate amount of solvent and adds the solvent to the sample container on the balance. Solution concentration is calculated by the software, and all sample information is stored on the computer hard disk drive. A sample label can be printed.
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