Product Description
The new BI-SFS sample filtration system provides a fast and convenient way to clean your light scattering samples, a necessity for samples smaller than 20nm. Utilizing Teflon ® tubing and nonreactive components, the BI-SFS is compatible with most sample filtration needs. Its modular design allows users to change pump heads and speeds to encompass virtually any possible application.
Dust in the samples is certainly the most common error that is found in light scattering measurements. Your success in making good light scattering measurements will depend on your ability to prepare clean samples. Most often dusty samples limit the reproducibility of the results. Unfortunately, dust can also yield systematic errors.
For instance, molecular weights calculated from a Zimm plot may be much too high; the average size and breadth of the distribution calculated from a dynamic light scattering (DLS) measurement may shift towards higher values; and the size distribution algorithms used in DLS are particularly prone to adding artificial components to the distribution when measurements are made in the presence of dust particles.
The BI-SFS readily cleans your sample in as little as 3 minutes. Difficult to clean aqueous-based samples are effortlessly rid of dust, making sample preparation an easy process. Whether due to inferior sample preparation methods or inherently "dirty" sample media, the BI-SFS will quickly and reliably reduce the effect of dust particles. When combined with the dust cutoff feature of the new, Windows™ BI-DLSW dynamic light scattering software, almost every sample appropriate for light scattering is now accurately measured.
The adjustable clamp permits users to employ a wide range of sizes, types and quantities of disposable filters. Depending on the application and the solvent, a single disposable filter can be used and re-used for filtering your samples, reducing the cost per sample. For faster filtration applications or exceedingly dusty samples, a series of filters is utilized. While this increases the cost per sample, greater time efficiency is realized.
Count Rate History of non-filtered Tap Water at 15° Scattering Angle
Count Rate History of filtered Tap Water at 15° Scattering Angle
The comparison of the two count rate histories illustrated above show a remarkable difference after filtering for only five minutes. The test was done using Brookhaven's BI-RC12 sample cell and a volume of 3.0 ml, with two 0.2 micron filters and two 0.1 micron filters in series. Your results may vary depending on sample volume, pump speed and water quality.
Notes
Not all samples are suitable for filtration. When samples are shear sensitive, do not filter. If samples adhere to a particular filter media, choose one suitable for your samples. Be certain to check the chemical compatibility of the sample against the composition of the filter.
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