Home » Brookhaven » Differential Refractometer BI-DNDC

Differential Refractometer BI-DNDC

Molecular Weight Products

BI-DNDC

Differential Refractometer

Brookhaven's BI-DNDC Differential Refractometer

Features at a glance

  • Fast instrument warm-up, ~ 1 hour!
  • Sensitivity, 2.5 x 109 ΔRIU
  • Autozero
  • Reference cell flush
  • 9 measurement ranges
  • DNDCW Windows™ software
  • Active temperature control to 80 °C
  • Wavelength selection: 620, 535 or 470 nm

Product Description

The BI-DNDC is a deflection type refractometer that may be purchased for use in either batch or GPC/SEC mode. In batch mode, the specific refractive index increment, dn/dc, is determined. This value is required as a parameter in molecular weight measurements using light scattering. In GPC/SEC mode, dn/dc is already known, and the instrument is used as a concentration detector for GPC/SEC applications.

Features

All major features are user programmable in order to achieve the maximum flexibility. The BI-DNDC can be set using the front panel controls and read using the LED readout or by an external computer. It includes a microprocessor, which allows user-friendly handling of all functions of the instrument, as well as refractive index and temperature data transfer to a personal computer via a standard serial interface.

Most importantly, warm-up time for the BI-DNDC is only one hour, much less than other models on the market.

Determination of dn/dc

The dn/dc determination requires calibration of the batch mode instrument with a solvent/solute combination with known dn/dc, typically KCl in water. The calculated constant is not solvent dependent and may be used for all further measurements. In batch mode, the instrument comes with BI-DNDCW software for use with an external PC. Included with the BI-DNDC instrument is a syringe kit with PEEK™ and Teflon ® tubing, fittings and syringes.

Sample may be recovered and reconstituted, if required. Typically, five or more concentrations, ranging from 0.1 to 10 mg/mL, are recommended. New instrument readings can be performed in a matter of minutes since it only takes ~ 0.5 mL of liquid to flush out the previous sample.

Determination of concentration

In this mode, the BI-DNDC serves as a highly sensitive concentration detector. Even better, with the right wavelength and the BI-MwA, the BI-DNDC becomes part of a system that eliminates GPC/SEC column calibration.

©2010 Brookhaven Instruments Corporation · 750 Blue Point Rd; Holtsville, NY 11742 USA · T: +1(631) 758-3200 · F: +1(631) 758-3255 · email: info@BrookhavenInstruments.com

This text was reproduced under the Creative Commons Attribution/Share-Alike License; additional terms may apply. See Terms of use for details

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: