Used Waters 2410 refractive index detector with a 10 µl flow cell and LED as light source. The detection range is 1.00 to 1.75 refractive index units (RIU). The flow rate is adjustable from 0.03 ml/min to 10 ml/min. Sensitivity settings include values 1, 2, 4, 8, 16, 32, 64, 128, 256, 512 and 1024. Analog outputs range from -2.0V to +2.0V Labprocure is responsible for this device.