Agilent Technologies OneNMR Probe Technical Overview
OneNMR Probe 400-700 MHz
Technical Overview
Introduction
The OneNMR probe represents a new class of NMR probes. This technology is
the most signifi cant advance in solution-state probe technology in over a decade.
The OneNMR probe is not a reworked version of a broadband or indirect detection
probe, but a new technology free of the performance trade-offs of those classic
designs. It is see an entirely new design with performance benefi ts unmatched by
other probes.
Sensitivity
The OneNMR probe is simultaneously
optimized for both high- and
low-band frequencies, and delivers
the performance advantages of
both the classic carbon probe and
the highly sensitive proton probe in
a single design. The signal/noise
(S/N) specifi cations for the family of
400-700MHz OneNMR probes is shown
in Table1, with excellent sensitivity on
both channels.
It is understood that actual S/N
performance will vary depending on
how well your system is shimmed.
The design and manufacturing of the
OneNMR probe results in a very tight
performance distribution so that all
probes are very similar. The S/N results
in Figure 2 were obtained using a
typical 400 MHz OneNMR probe with
an Agilent 400-MR magnet.
The proton sensitivity data in Figure 1
is 20 % greater than the specifi cation.
These data illustrate one of the dangers
of comparing probes on the basis of
published specifi cations alone. Probe
specifi cations for a given vendor (probe
to probe) tend to be consistent, making
direct within-vendor comparisons easy.
However, direct comparisons between
vendors are much more diffi cult
owing to differences in methods and
philosophy. When sensitivity is used as
a basis for probe selection, your safest
bet is a direct head-to-head comparison
with the same sample (yours) and
operator (you).
Table 1. 400 -700 MHz OneNMR Probe Sensitivity Specifi cations.
400 500 600 700 Sample Tube
1
H 480:1 730:1 900:1 1150:1 0.1 % Ethybenzene Wilmad 545-pp
13
C 225:1 300:1 380:1 460:1 0.1 % Ethybenzene Wilmad 545-pp
15
N 20:1 25:1 35:1 45:1 90 % Formamide Wilmad 535-pp
31
P 90:1 135:1 170:1 220:1 0.0485 M TPP Wilmad 535-pp
19
F 550:1 800:1 1050:1 0.05 % TFT Wilmad 535-pp
A
C
Figure 1. 400 MHz OneNMR Probe High & Low Band Sensitivity (A) Proton S/N, (B) Fluorine S/N,
(C) Carbon S/N.
B
2
The OneNMR Probe lock sensitivity
is also enhanced to provide a more
stable lock and to support fast gradient
shimming for increased fl exibility (e.g.
3mm tubes) and greater ease-of-use.
Sensitivity, while important, is just
one aspect of probe performance and
only part of the story. The sections
which follow will introduce you to the
advantages of the OneNMR probe that
extend far beyond sensitivity alone.
Pulse Performance and
Lineshape
The 400-700 MHz OneNMR Probes
provide superior lineshape both
spinning and non-spinning which means
ease of shimming and well resolved
spectra. The lineshape specifi cations
are shown in Figure 2, along with an
example of the proton-decoupled 13C
NMR spectrum of dioxane.
400-700 MHz OneNMR Probe
Lineshape Specifi cations
Spinning Non-spin
13C1
50 % ≤ 0.15 0.45 0.8
0.55 % ≤ 1.5 5.0 7.0
0.11 % ≤ 3.0 10.0 14.0
Sidebands ≤ 1 % 1 %
Figure 2. OneNMR Probe lineshape specifi cations (left) and a spinning 13C dioxane example.
Table 2. 400-700 OneNMR Probes pulse performance.
PW90 400 Mhz 500 MHz 600 MHz 700 Mhz Sample
1
H 7 µsec 8 µsec 9 µsec 10 µsec 1 % 13C-Iodomethane
13
C 8 µsec 10 µsec 9 µsec 10 µsec 1 % 13C-Iodomethane
15
N 14 µsec 20 µsec 18 µsec 20 µsec 90 % Formamide
31
P 8 µsec 15 µsec 12 µsec 15 µsec 0.0485 M TPP
19
F 8 µsec 10 µsec 10 µsec 0.05 % TFT
1
H
H
13
C Lineshape
Decoupled Dioxane
0.08 50 %
0.67 0.55 %
1.40 0.11 %
The OneNMR probe’s modern design
and effi cient power handling leads to
excellent pulse performance. The PW90
pulse widths for the 400-700 MHz
OneNMR probes are listed in Table2.
These relatively short PW90’s are ideal
for experiments requiring excitation
or decoupling over a wide spectral
window (e.g. 19F).
3
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