Question L7.1. During a pulse calibration, the 360° pulse
was found at 100 s. What is the radiofrequency field of
the pulse in Hz? Is this radio-frequency field sufficiently
strong to give hard pulses over the full range of 1H
chemical shifts (0 - 10 ppm) on a particular spectrometer
having a Larmor frequency of (w1/2rt) = 900 MHz.
Question L6.1. A particular spectrometer has a BO field
which gives a Larmor frequency of 900 MHz for 1H; the
RF field strength (w1/2rt) has been determined to be 5
kHz. Suppose the transmitter is placed at 5 ppm.
Compute the offset (in Hz) of a peak at 10 ppm, and then
compute the tilt angle of the effective field, 0, for a spin
with this offset.
Where is the magnetization vector after 90° (x)-180°(x)? -
Can you use a superconducting magnet that has a
homogeneity of 1 part in 108 to measure a P-
containing sample that has a 31P linewidth of 25 Hz
on a spectrometer operating at a 1H frequency of 400
MHz Y1H, Y31P are 26.75 x107 and 10.08x 107
A spectrometer operates at 800 MHz for 1H proton,
and it is desired to record a spectrum covering a shift
range of 15 ppm. Assuming that the receiver
frequency is placed in the middle of this range, what
range of frequencies is covered by the spectrum, and
what would be the dwell time have to be?
What is wrong with this spectrum?
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