The integral of the peak associated with the reference sample is used to calibrate the instrument response. Both the sample and the reference are weighed out and co-dissolved into a single solution. One method of calibrating the NMR spectrometer is with an internal standard. Quantification using any analytical method is no more than calibrating an instrumental response with a known reference, and then calculating the concentration of an unknown sample from the measured instrument response. The peak positions are shown above the spectrum and range from 3.64 to 4.99 for this sample. If the peaks match, then the sample passes the peaks comparison test. The peak positions in the spectrum are compared to a peaks list determined from a standard material. A similar set of tests is used for sodium ascorbate. Here a single NMR spectrum is acquired and analysed with three different tests: peaks, multiplet, and nuclides count comparisons to quickly identify ascorbic acid. The United States Pharmacopeia method for identification of ascorbic acid requires both FT-IR and a reducing sugar chemical test because neither has the specificity on its own. Here we show a method for identification of ascorbic acid, which is a common vitamin sold on its own as well as in many dietary supplements. Depending on the degree of specificity required, this can be a simple peaks comparison or can incorporate other tests related to peak splitting and integral intensities. NMR spectra can be used to identify compounds. Using these peak positions and relative intensities, the compounds, mixtures and impurities in a sample can be identified or quantified. Sample concentrations and purities can be easily measured from known peaks once the proportionality constant is calibrated using a reference of known concentration. In other words, the peaks are a chemical signature and the sample concentration is proportional to the intensity of the NMR signal detected. The peaks in the spectrum will appear in predictable locations in the spectrum and their intensities will be proportional to the number of nuclei in the sample. These same properties result in NMR being excellent for quantification and identification. This is because the electronic structure, the bedrock of chemistry, is what determines the chemical shift, while the number of nuclei determine the coupling and relative intensities. The chemical structure of a small molecule dictates a rational spectrum. NMR is best known for its use in structure determination. Identification, Quantification (qNMR) and Mixture Analysis

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