Gravimetric Dilution: More Accurate than Volumetric

Solutions prepared using volumetric glassware are inherently inaccurate because of the density change of the solvent as the laboratory changes temperature. The magnitude of this error can be understood by referring to Table 1. Since Borosilicate (Pyrex™) glassware changes volume by only 0.013% over the same temperature span, the errors caused by this volumetric change can easily be as high as 0.5%.

Modern analytical instruments can routinely measure to an accuracy much better than 0.5%; however, in order to reach this potential, the solutions used in these techniques must be prepared to an accuracy three to ten times better (0.16% to 0.05%).

What are the costs of solvent mixing & solution preparation using the volumetric method vs the gravimetric method (PhasePrep II)?

The cost of purchasing, replacing and cleaning of volumetric glassware. 
With the PhasePrep II this is replaced by the cost of uncalibrated solvent containers.

The cost of wasted solvent.
With the PhasePrep II, 135 ml or 653 ml of a solution can be prepared as easily as one liter. Solvent waste is minimized.

The safety cost of handling solvents.
The PhasePrep II is a closed system. The exposure to spilled solvents, broken glassware and harmful solvent vapors is reduced.

The cost of loosing laboratory integrity.
This is the highest cost of all. What price can be put on mis-identifying a peak in a chromatogram because the solvent was not mixed accurately or a mislabeled solvent was used? The PhasePrep II prepares mixtures to an accuracy of a few hundreths of one percent or better— every time. A label is also printed to document the preparation. This minimizes the cost of re-works, non-conformance investigations and the costly delays that could result in not shipping finished product.