NMRsfrom Perkin-Elmer, pioneer of the highly stable permanent magnets.

THE MODEL R-20B. F o r i H, 19Fl

13c , 31 p, 1 1 B , 77Se and more. A high performance instrument

with multi-nuclear capabil i ty. Offers S / N > 3 0 : 1 · Resolu­tion 0.3 Hz · Wide range VT • Heteronuclear decoupling

' · Wide band decoupling • Spectrum accumulat ion.

THE MODEL R-12B. Compact spectrometer for routine and research applications that measures 1 H, 19F. Lower in cost, easier to operate. Also offers the fol lowing features: S / N > 3 0 : 1 . · Resolution 0.35 Hz · Wide range VT · Double resonance · Spectrum accumulat ion.

PERKIN-ELMER

Circle No. 140 on Readers' Service Card

ANALYTICAL CHEMISTRY, VOL. 43, NO. 4, APRIL 1971 · 33 A