Question

Compare the applications of five instruments(NMR instrumentaion - gas chromatograph -HPLC- CHN ANALYZER -single beam instrument) in analytical chemistry . The applications should be related to the analysis of different types of samples.Give examples of how can a particular analyte be determined by each instrument.

Answer 1

NMR	GC	HPLC	CHN analyser
NMR is used for elucidating the structure of unknown organic molecule in solution state, solid phase and as well as non-crystalline materials. Structure elucidation can be done by 2D NMR techniques like HSQC, HMBC, NOE, COSY, ROSEY, DEPT etc. Diasteromers can be identified by NMR. Obsolete configuration of the compound can be deduce by NMR	Purity of organic compounds especially with non-chromophores can be determined by GC instrument. Chiral purity of the organic compounds can also be deduce by GC. GC is a separation method or technique in where volatile compounds (in mixtures) are separated. Quantification of solvents or organic compounds can also be determined using reference standard. Organic volatile impurities are determined and released for drug substances and drug product.	HPLC is the technique used to separate or resolute a mixture of organic compounds particularly compounds having chromophores. Its purity can be determined for release of drug substances (API) and drug product. Quantification of compound impurities can be determined using HPLC. Limit of quantification and limit of detection is used by HPLC for release of drug substances.	The CHN analyser is used to measure the percentage composition of carbon, hydrogen and nitrogen elemental. This is used to determine the purity of the compound (elemental purity).