Greetings,
I have suddenly developed a problem with 27 Hz artifact peaks that appear
around each peak in a 1H NMR spectrum (very ugly on the most intense peaks
but proportionately also present around the TMS peak - they seem to be
pretty much anti-phase - they do not signal-average away and often get
bigger when you reach the magic multiples of 16 on the co-averaging. They
are present spinning and non-spinning and also present when the sample is
run unlocked. They are about the same size as the 13C satellites. Other than
these artifacts cycling through the spectrum everything seems fine - shim
and sensitivity are good.
The system is a Varian Mercury-MVX300, with a 5mm ATB probe with PFG,
running VNMRJ 4.2
Not sure if the same artifacts show up in 31P or 13C spectra - will know
soon.
Thanks for any help,
John
John C. Edwards, Ph.D.
Principal - Process NMR Associates, LLC
84 Patrick Lane, Ste 115, Poughkeepsie, NY 12603
Tel: (845) 240-1177, Mobile: (203) 241-0143
Received on Thu Jun 27 2019 - 07:56:11 MST