Background in ¹¹B measurements

In ¹¹B measurements, similarly to ²⁹Si measurements, background signals may sometimes be a problem. Although the background derived  from sample tubes can be reduced by using quartz or PTFE sample  tubes, those from glass and ceramics of the probe cannot be removed.

JEOL revised the glass and ceramic materials of the standard probe  parts and successfully reduced the ¹¹B background signals.

40TH5AT/FG2（5mmφ）

40T10/AT(10mmφ）

The above figure shows the ¹¹B spectra observed using a 400 MHz  spectrometer and 5 mm -(left) and 10 mm -(right) probes. The ¹¹B  spectra without sample tubes (top) manifest almost no background  signals derived from the probes.

The middle and bottom figures show the ¹¹B spectra of phenylboric acid (1.0 x 10^-2 M). Although heat-resistant glass sample tubes are commonly used, they may cause background (bottom). Therefore, quartz or PTFE sample tubes (middle) are recommended in ¹¹B measurements.