Fast D-PAS
Overview
High throughput pKa measurement on GLpKa and PCA200 with D-PAS
- Fast hybrid pH/UV method saves time
- Only 4 minutes per sample!
- Easy assay set-up
- Highly automated
- pKas between 2 and 12
- Up to 50 samples in four hours
- Accurate, repeatable results
- Aqueous or cosolvent methods
- Measures labile samples before they decompose
Fast D-PAS is a software module that runs in RefinementPro 2. If you are running a GLpKa and D-PAS, Fast D-PAS software will enable you to measure pKa values very quickly.
Titrations are done in the presence of a unique linear buffer solution. This allows the pH electrode to reach a stable value very quickly after each addition of titrant.
Fast D-PAS measures pKa for water-soluble samples in four minutes. Water-insoluble samples are measured in water-solvent mixtures using a Multisweep titration. A sample is prepared in water plus buffer plus cosolvent, and titrated with base from low to high pH. At the end of the first titration, the solution is titrated with acid to low pH, then back to high pH, and so on. Each titration dilutes the cosolvent, and additional water can be added between titrations if required. It takes less than 10 minutes to do a 3-titration Multisweep between pH 2 and 12, and the cosolvent can be diluted significantly, say from 40% to 20%. A Yasuda-Shedlovsky extrapolation to the aqueous pKa based on 3 points is plotted automatically. Reference spectra for Fast D-PAS experiments are obtained from a Buffer Calibration Titration. In this procedure, a blank solution is titrated over the full pH range, and the UV spectra are saved after each addition of titrant. This procedure provides reference spectra of the highest quality.
Literature
Five publications since 2005.
Click here for references
To Download Fast D-PAS Literature
Click here to go to our online form
Sirius appointed as distributors for Kibron Delta-8
24.7.08
Sirius are now the exclusive distributors in UK, USA and Canada for the Kibron Delta-8 system for measurement of surface tension and phospholipidosis.
Cambridge scientists set solubility challenge
11.8.08
A new paper from scientists using Sirius solubility techniques at the University of Cambridge asks "can you predict solubilities of 32 molecules using a database of 100 reliable measurements?".
BPC 2008
09.9.08
John Comer from Sirius is giving a presentation on solubility and supersaturation, and their effects on predicting oral absorption.
AAPS Annual Meeting
16.11.08
Sirius will have a booth at this years AAPS Annual Meeting in Atlanta, Georgia.