9.1 FID

Free Induction Decay of an NMR signal in a 1D experiment with a 50 msec expansion showing the digitization of the signal.

9.2 Digital resolution

All spectra at 600 MHz with 10 ppm sweep width (6000 Hz). The digital resolution is shown next to spectrum.

	number of data points (np): 4K Fourier number (fn): 4K acquisition time: 0.35 sec zero-filling: none
	number of data points (np): 8K Fourier number (fn): 8K acquisition time: 0.70 sec zero-filling: none
	number of data points (np): 16K Fourier number (fn): 16K acquisition time: 1.40 sec zero-filling: none
	number of data points (np): 24K Fourier number (fn): 32K acquisition time: 2.00 sec zero-filling: 1.33 x
	number of data points (np): 24K Fourier number (fn): 64K acquisition time: 2.00 sec zero-filling: 2.66 x

9.3 Sep-Pak filtration for carbohydrates (courtesy Dr. Gordon Alton)
For oligosaccharides with hydrophobic aglycons the following conditions are recommended for C18 Sep-Pak cartridges:

1. Wash with 5 mL of methanol then 10 mL of water

2. Load oligosaccharide in water or buffer, the more dilute the better, use a flow rate of less than 10 mL/min (slower is better)

3. Wash cartridge with 10 mL of water (flow rate is not important),
   keep all solutions until you know where the carbohydrate is!

4. Elute oligosaccharide with 5 or 10 mL of methanol.

One C18 Sep-Pak can hold up to 10 mg of an octyl glycoside trisaccharide, but is different for each sugar, aglycon, flow rate and load buffer situation. Determine experimentally what works best for your compound.

HETCOR, i.e. direct detection of heteronuclei in 2D NMR is inefficient and the information of experiments recorded with indirect detection (gHMQC, gHMBC and similar techniques) is nearly identical as shown below:

Methods to record correlations between protons and heteroatoms:

(a) values relative to HETCOR; based on use of an indirect detection probe (sensitivity gain is lower with sw and asw probes)

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