Low concentration
samples can be extremely challenging, especially 13C which has
only 1% natural abundance. Without a field frequency lock, the problem of
magnet drift can be intolerable. Anasazi Instruments has solved this problem
in a unique way; Block Averaging with Peak Registration
(BAPR). In the BAPR experiment, blocks of data are acquired (with or without
shimming between block acquisitions). The data is stored as an array of
FID's. All of the blocks are Fourier transformed and, using a strong
resonance as the registration peak, all of the spectra are then aligned. The
individual spectra are converted to a single spectrum with
significantly
enhanced signal-to-noise.
Concentration: 0.2 M + 1% TMS in Bezene-d6
Below is the result of an
overnight acquisition of 0.2 M Cholesterol using the BAPR program.
The inset plot indicates the resolution obtainable at the carbon frequency
(15.1 MHz).
