Refiactometer detectors

The concentration of lactose and fermentation products such as succinic acid and acetic acid was determined by high-performance liquid chromatography (Waters, Milford, MA) with a KC-811 ion exclusion column and a waters 410 differential refiactometer detector. The mobile phase was 0.1% H3PO4 solution at a flow-rate of 1 mL/min. The temperature of the detector and of the column ware maintained at 35 and 60 °C, respectively. The succinic acid yield was expressed as the amount of succinic acid produced from 1 g lactose consumed during the fermentation process. 

Samples were analyzed using an SEC system consisting of a Hewlett Packard liquid chromatograph 1090 and a Wyatt interferometric refiactometer detector. The mobile phase was toluene pumped at a flow rate of 1 mL/min. 100 pL of sample solution (5 mg/mL) were injected. The stationary phase consisted of 3 columns (300 mm x 8 mm ID) filled with PSS SDV gel (10 , 10, 10 A 5 pm). The software of PSS Mainz (WIN GPC) was used for data acquisition. 

It is often useful to monitor simultaneously not only concentration and molar mass but also composition of eluting mactomolecules. Detectors that for example combine a differential refiactometer with the ultraviolet photometer, and the flowthrough light scattering monitor or the flow-through viscometer are comercially available. 

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