NMR and HPLC in organic synthesis laboratories

In continuation of our effort to let you know some of the routine equipments/instruments used for research, this time Rameshwor Pandit  from Yeungnam University, South Korea presents two key instruments used in his Organic Synthesis Lab: NMR system and HPLC. These instruments are widely used in research and routine analysis laboratories for variety of applications.

(1)   NMR Spectroscopy

This system consists of mainly four parts (1) superconducting magnet (2) detector and amplifier (3) console and (4)  spectrum display.
Varian VNS 300 MHz                                                   

At the beginning, sample solution is prepared in deuterated solvent. Next, the computer program is opened (above is Varian VNS 300 MHz) and set some of the parameters like temperature, spinning.  As soon as sample is inserted into the magnet, the system is locked to a particular deuterated solvent. The Varian system works on automated shimming while Bruker type of system works on mechanical shimming. Now the sample is scanned setting some acquisition parameters like no. of scans, time, sample FID. As the sample is scanned, computer shows spectrum which is processed to get NMR spectrum as shown in computer display (below).

Computer Displaying Spectrum

Superconduting magnet of  7.4 Tesla with  probe at the buttom (Varian VNS 300 MHz)

OXFORD 900 MHz NMR Magnet

(2) High Performance Liquid Chromatography (HPLC)
HPLC is a high pressure column chromatography for the separation of molecules, particularly chiral HPLC has occupied the broad space in recent synthetic chemistry. We have this old HPLC which uses manual way of sample injection. The most advanced HPLC of these days are assembled with automatic injection system. Big glass bottle contains solvents.

JASCO Co-2056 Plus Column JASCO Co-2075 Plus UV/VIS Detector

Sample to be analysed is injected manually/automatic while the pump moves the solvent and sample through the column, the detector detects the components of sample and measures the retention time. The retention time differs for each component as these components are different in chemical constituents and hence differential interaction persists between columns while the sample passes through.

Prepared and Posted by
Rameshwar Pandit

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