a high-performance liquid chromatographic assay for methotrexate and its metabolites , 7-hydroxy-methotrexate , 4-amino-4-deoxy-n10-methyl-pteroic acid and 7-hydroxy-4-amino-4-deoxy-n10-methyl-pteroic acid in the range 10 microg/l to 50 mg/l ( 2.2 x 10 ( -8 ) to 1.1. x 10 ( -4 ) m ) has been developed using l-tryptophyl-l-glutamic acid as internal standard .
C0002520
amino
C0061472
l