Protocol 1—Sample Loading for FAB-MS Analysis

Dissolve the sample in either 5% acetic acid (for underivatized samples) or methanol (for derivatives) to such a concentration that 1 pi aliquot of the sample contains the desired amount of sample for FAB-MS analysis. 

Smear about 1 pi of the matrix onto the metal target which is attached to the end of the FAB probe. 

Load about 1 pi of the sample on the surface of the matrix using a micropipette 

Introduce the probe into the FAB source and collect data immediately. 

When a wide mass range of scanning is required, e.g. m/z 4,000 to 200, it may be necessary depending upon instrument type to acquire scans covering the high and low mass range separately with two separate sample loadings. 

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