² H SOLCOR: A novel tool for reducing volume variation as a source of error in external standard quantitative NMR

Tube to tube volume difference presents a challenge in obtaining correct external standard quantitative NMR (esqNMR) results. Deuterium (² H) NMR is easily observable, intrinsically quantitative, present in all samples, free of interfering signals, and insensitive to probe tune/match and sample saltiness. These properties make ² H peak integral an ideal parameter in esqNMR for correcting volume differences between the reference standard and analyte. We demonstrate a novel and practical technique abbreviated as "² H SOLCOR" (² H SOLvent CORrected), where the ² H peak integral from the solvent is used as a universal internal standard to correct volume variations in NMR tubes, thereby improving accuracy and precision of esqNMR method. Herein, this simple yet effective technique is described, and practical considerations for successful implementation are presented. ² H SOLCOR can be applied anywhere esqNMR is used, including where precious samples need to be accurately quantified for qualification as an authentic analytical standard.