Drug Metabolism in Drug Design and Development Basic Concepts and Practice

TABLE 12.10 (

Continued

)

Mode

Setup

Advantages

Limitations

Loop-storage

or SPE/transfer

LC chromatography is performed

first with collection of peaks ina loop cassette or SPE cartridgeusing the UV or MS signals

LC chromatography could be

performed independently fromthe NMR experiments

Sample could decompose during

the storage period

The stored fractions in the loops

or SPE are then transferred intothe NMR flow probe foranalysis

Since the chromatography is not

stopped, issues with peakbroadening in the stop-flow modeare eliminated. Eliminates crosscontamination problems

Requires the use of special

equipment to direct the flowthrough different pathways

Computer control of the

instrument is essential in thismode of operation

Multiple experiments on each

sample are possible includingHeteronuclear experiments suchas

1 H



15

N

393