Manual v Automatic polarimeters
Although polarimetry is a mature technique, today's instrumentation provide features and benefits that purely manual-optical systems do not. Busy labs processing multiple samples per day now have the option of automated data capture, variable wavelength and temperature, and (with modern instruments such as the Krüss P8000) up to 0.002 deg accuracy and 0.001 deg resolution. At this level of precision, process industries and formulators can set extremely narrow quality standards.
A traditional manual polarimeter requires a skilled operator and the process can take considerable time to perform.
Manual polarimetry still has its place, for low-throughput labs and for training, but for many modern industries, such as pharmaceutical, chemical, sugar, and food processing, an automatic polarimeter is the better choice and makes the process much quicker. Lab productivity is greatly improved, and the investment pays real dividends.
Features of automatic polarimeters
· Compatible with Good Laboratory Practice (GLP) and US FDA 21 CFR part 11.
· Accurate reading is provided in a few seconds or less.
· Operator-induced errors are eliminated.
· Measurement consistency is greatly improved – important for regulated laboratories.
· Touchscreen controls and clear digital readout
State of the art digital polarimeters are intended for use in FDA-regulated sectors due to their GLP compliance, integrated user management and full network support, for simple connection to the laboratory environment and a LIMS. Measuring time is reduced to around one second, regardless of the rotation angle of the sample. Continuous measurement is possible (for example for kinetic investigations - investigating kinetic reactions by measuring optical rotation as a function of time - or in HPLC use). The connection of a temperature-controlled gauge head permits extremely accurate measurement.
A digital polarimeter can be connected to a PC or linked to a network via an Ethernet interface. If there is internet access, remote maintenance and fault diagnosis are also possible.