Varian Associates

Nuclear Magnetic Resonance. In 1994 there were three principal vendors of nmr instmmentation in the U.S., Bmker Instmments (Billerica, Mass.), JEOL USA, Inc. (Peabody, Mass.), and Varian Associates (Palo Alto, Calif.). Details of instmmentation are best obtained directly from manufacturers. A schematic illustrating the principal components of a ft/nmr spectrometer is shown in Eigure 3. 

Cyclitol Spectra at 220 MHz with the Superconducting Solenoid. In 1964, Nelson and Weaver (34) at Varian Associates constructed a superconducting solenoid with which proton spectra can be observed at 51.7 kilogauss (220 MHz.) or even higher fields. Other nuclei have been observed at suitable field/frequency combinations. 

The 220 MHz spectra shown in the figures were recorded at Varian Associates (see Acknowledgement) on their Model HRSC-IX or -220 Spectrometer. 

Based in part on work aided by a grant (CA-07250) to the University of San Francisco from the National Cancer Institute, U.S. Public Health Service. We are greatly indebted to the scientific staff of Varian Associates, Palo Alto, for the 220 MHz proton magnetic resonance spectra, and... 

Current address Varian Associates, Inc., 2700 Mitchell Drive, Walnut Creek, CA 94599... 

Tohoku University, 120,232 U.S. Army Medical Research Institute of Infectious Diseases, 176 U.S. Food and Drug Administration, 29,241 University of Alaska, 29 University of British Columbia, 312 University of California—Berkeley, 107,290 University of Chicago, 204 University of Florida, 279 University of Hawaii, 232 University of Maryland, 78,107333 University of Miami, 166 University of Rhode Island, 21 University of Utah, 256 University of Virginia, 347 University of Zurich, 347 University of the Philippines, 256 Varian Associates, Inc., 66 Wright State University, 87 Yale University, 29... 

Figure 3.8 Alternative designs for cold on-column injectors, h, Injector with a duck bill valve (Hewlett-Packard), B, an injector with provision for secondary cooling of the column inlet (Carlo-Erba), and C, a temperature- programmable on-column injector with its own oven isolated from the column oven (Varian Associates).

Figure 3.9 Cross-sectional view of a flame ionization detector. (Reproduced with permission from Varian Associates).

Varian Associates, High Resolution NMR Spectra Catalogue, Varian, Palo Alto, CA (1962/3), Vol. 2. 

Figure 4.23 from McNair and Bonelli, Basic Gas Chromatography, with permission from Varian Associates, Inc. 

The 100 MHz pmr spectrum of a deutei> ochloroform solution containing tetramethylsilane as an internal reference was obtained on a Varian Associates XL-100-15 spectrometer equipped with a Nicolet pulsed Fourier accessory.32 (Figure 3.)... 

The proton NMR spectrum of griseofulvin (Figure 2) was obtained in DMSO-d, solution (cone, w/v = 10 mg/0.40 ml) containing TMS as internal reference utilizing the Varian Associates CFT-20 Spectrometer operating at a frequency of 79.5 MHz. The chemical shifts (<5, ppm) are with reference to TMS. The experimental conditions are ... 

The carbon-13 NMR spectrum of griseofulvin (Figure 3) was obtained at ambient temperature in DMSO-d containing TMS as internal reference utilizing Varian Associates XL-100-15 spectrometer equipped with Fourier accessories The system was locked to the deuterium resonance frequency of the solvent, and operated at a frequency of 25.2 MHz for carbon-13. The chemical shifts are reported ( c, ppm.) from the Internal standard TMS. 

The nuclear magnetic resonance spectrum of sodium valproate as shown in Figure 3 was obtained on a Varian Associates T-60 NMR Spectrometer in deuterium oxide containing tetramethylsilane as the internal standard. The spectral peak assignments (2) are presented in Table I. 

Introduction to Extended Interaction Oscillators, Data Sheet 3445 5M 11/75, Varian Associates of Canada, Ltd. (Now CPI), Georgetown, Ontario, Canada, 1975. 

Graphite furnace Flame graphite furnace Varian Associates SpectrA A30 + 40 multi-element analysis Method storage SpectrA AI0 (low cost, single beam) SpectrA A20 (medium cost, double beam) SpectrA A300/400 multi-element analysis, centralized instrument control STA 95 and GTA 96 graphite tube atomizer units - compatible with ail SpectrA A instruments... 

Varian Associates Spectr AA 30/40 and Spectr AA 10/20 Varian Associates Ltd... 

Varian Associates Ltd 28 Manor Road Walton on Thames Surrey KT12 2QF UK... 

PS Analytical Ltd Model PSA 10.002 Dr P B Stockwell Varian Associates Ltd Arthur House, Far North Building Cray Avenue, Orpington Kent BR5 2TR UK... 

Johnson, EL and R. Stevenson, Basic Liquid Chromatography , Palo Alto, Varian Associates Inc., 1978. 

Figure 4.7 Effect of high organic modifier concentration on peptide retention. Data obtained using an octadecyl column and 20 mM ammonium acetate acetonitrile mobile phases. (Reproduced from C.T. Wehr and L. Correia, LC at Work LC-121, Varian. With permission from Varian Associates.)...

Varian Research Center, Varian Associates, Inc., Palo Alto, CA 94303 Varian Instrument Group, Varian Associates, Inc., Wabiut Creek, CA 94598... 

Nuclear spins, moments, natural abundances, and resonance frequencies are summarized in a tabulation available from Varian Associates, Palo Alto, California and reproduced in the review article by Pake IS) and the book by Losche 12). 

A commonly used EPR spectrometer, similar to that commercially sold by Varian Associates, Palo Alto, California, is shown diagrammatically in Fig. 21. The spectrometer consists of a four-arm microwave bridge generally known as a hybrid tee. The action of this microwave bridge is somewhat... 

Many contributed to the success of the symposium. The executive and members of the Macromolecular Science Division thank the following firms for fiscal support Polysar Limited Abitibi Paper Company Reichhold Limited Xerox Research Centre of Canada Limited Varian Associates of Canada Glidden Company Domtar Limited DuPont of Canada Shell Canada Gulf Oil Canada and the Dunlop Research Centre. A special vote of thanks is extended to the speakers at the symposium and to the authors for their excellent presentations and for their cooperation in putting it together. J. Comstock of the American Chemical Society showed understanding and patience in bringing this volume to print. 

Fig. 3. Long range and one-bond carbon-13 satellite spectrum of a 5% w/w solution of ethanediol in D2O at 94°C. 16 transients were measured on a Varian Associates Unity 500 spectrometer using the sequence of fig. 1, with 2.5 s presaturation, a t value of 100 ms, spin lock pulses of 450 ps, no homospoil pulse, and no homodecoupling during acquisition.

Fig. 4. (a) 300 MHz proton spectrum and (b)-(e) selective reverse INEPT spectra of 28% menthone (Aldrich) in acetone-ds, measured using a 5 mm sample in the 10 mm broadband probe of a Varian Associates XL300 spectrometer using the sequence of fig. 1. The sample contains substantial quantities of isomenthone, seen clearly in the methyl region of trace (a). Spectra (b) to (e) used selective excitation of carbon sites 6, 7, 2 and 8, respectively, with delays 2r of 3.85, 3.85, 1.92 and 1.54 ms. 32 transients were used for each trace no spin lock pulses or 180° pulses were used. Traces (b) to (e) have a vertical scale lOOOx that of trace (a). No homodecoupling was used during acquisition. 

PS118, PS160, PS340, PS463, PS537, and PS732) were obtained from Petrarch Systems, Inc. For the IR spectra a Nicolet MX-10 FT-IR spectrometer was used at a resolution of 1 cm". The UV spectra were measured on a Model DMS 90 Varian Associates UV-Visible spectrophotometer which was connected to an Apple 11+ desktop computer, equipped with an in-house modified Varian Associates software package. Other experimental details are described elsewhere(3). 

B-63M150500 Varian High Resolution NMR Spectra Catalog , Varian Associates, Palo Alto,... 

Varian Associates contributed the time and talents of its NMR Applications Laboratory. We are indebted to Mr. N.S. Bhacca, Mr. L.F. Johnson, and Dr. J.N. Shoolery for the NMR spectra and for their generous help with points of interpretation. 

Figure 22-4 Mass spectra of the sedative pentobarbital, by using electron ionization (left) or chemical ionization (right). The molecular ion (M, m/z 226) is not evident with electron ionization. The dominant ion Itom chemical ionization is MH. The peak at m/z 255 in the chemical ionization spectrum is from M(C2H5). [Courtesy Varian Associates, Sunnyvale. CA.J...

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