(R)-1-(4-Fluorophenyl)-1-(3-(methyl(methyl-d3)amino)propyl)-1,3-dihydroisobenzofuran-5-carbonitrile oxalate,(R)-1-(4-Fluorophenyl)-1-(3-(methyl(methyl-d3)amino)propyl)-1,3-dihydroisobenzofuran-5-carbonitrile oxalate,"Labeled Citalopram, intended for use as an internal standard for the quantification of Citalopram by GC- or LC-mass spectrometry.",Citalopram Stable Isotopes