Bruker instruments

Bruker instruments use quadrature detection, with channels A and B being sampled alternately, so the dwell time is given by ... 

The matrix obtained after the F Fourier transformation and rearrangement of the data set contains a number of spectra. If we look down the columns of these spectra parallel to h, we can see the variation of signal intensities with different evolution periods. Subdivision of the data matrix parallel to gives columns of data containing both the real and the imaginary parts of each spectrum. An equal number of zeros is now added and the data sets subjected to Fourier transformation along I,. This Fourier transformation may be either a Redfield transform, if the h data are acquired alternately (as on the Bruker instruments), or a complex Fourier transform, if the <2 data are collected as simultaneous A and B quadrature pairs (as on the Varian instruments). Window multiplication for may be with the same function as that employed for (e.g., in COSY), or it may be with a different function (e.g., in 2D /-resolved or heteronuclear-shift-correlation experiments). 

The proton NMR spectrum of miconazole nitrate was obtained using a Bruker Instrument operating at 300, 400, or 500 MHz. Standard Bruker Software was used to execute the recording of DEPT, COSY, and HETCOR spectra. The sample was dissolved in DMSO-d6 and all resonance bands were referenced to the tetramethyl-silane (TMS) internal standard. The 1H NMR spectra of miconazole nitrate are shown in Figs. 5-7 and the COSY 1H NMR spectrum is shown in Fig. 8. The H NMR assignments for miconazole nitrate are provided in Table 3. 

The carbon-13 NMR spectra of miconazole nitrate were obtained using a Bruker Instrument operating at 75, 100, or 125 MHz. The sample was dissolved in DMSO-d6 and tetramethylsilane (TMS) was added to function as the internal standard. The 13C NMR spectra are shown in Figs. 9 and 10 and the HSQC and HMBC NMR spectra are shown in Figs. 11 and 12, respectively. The DEPT 90 and DEPT 135 are shown in Figs. 13 and 14, respectively. The assignments for the observed resonance bands associated with the various carbons are listed in Table 4. 

The H NMR and the 13C NMR spectra of niclosamide were obtained using a Bruker Instruments system operating at 300, 400, or 500 MHz (proton NMR), or at 75, 100, or 125 MHz (carbon NMR). Standard Bruker software was used to obtain DEPT, COSY, and BETCOR spectra. All measurements were obtained with the compound being dissolved in deuterated dimethyl sulfoxide (DMSO-d6). 

The proton nuclear magnetic resonance (NMR) spectra of primaquine diphosphate was obtained using a Bruker instrument operating at 300, 400, or 500 MHz. 

The CP/MAS Accessory Product Description Manual, Bruker Instruments, Inc., Billerica, Mass., 1987. 

X-ray powder diffraction patterns of samples heated at temperatures between 20 and 500 C were recorded in situ by using a Philips instrument equipped with vacuum camera (5x10 Pa). Heating rates of 5 C min l and CuKot radiation were used. Infrared spectra were obtained using a conventional greaseless IR cell the procedure and sample preparation have been described elsewhere (6). Al MAS-NMR spectra were recorded using a 400 MHz Bruker instrument. 

The proton magnetic resonance spectrum of indinavir sulfate shown in Figure 12 was obtained using a Bruker Instruments model AMX-400 NMR spectrometer operating at a frequency of 399.87 MHz as an approximate 4.16 % w/v solution in deuterium oxide. The HOD reference (chemical shift equal to 4.8 ppm) was used as the reference. Signal assignments are tabulated Table 7, following the numbered structural formula below [11]. 

Permission to use published material was granted by Finnigan MAT, American Society of Mass Spectrometry, John Wiley and Sons, Inc., Journal of Chemical Education, and Organic Magnetic Resonance. Processing software was furnished by Herbert Thiele (Bruker Instrument Corp.). 

Adjust the receiver gain by using the RGA command (for a Bruker instrument). 

U.K.), with a normal sweep width of 1000 Hz and sweep time of 500 s. Fourier transform PMR spectra were recorded using a Bruker WH 300 instrument (Bruker Instruments Inc., Manning Park, Billerica, MA 01821, USA) and methanol-d as solvent (NMR Ltd). 

Current address Bruker Instruments, Inc., Manning Park, Billerica, MA 01821... 

The next stage in the development of GD-FT-ICR instrumentation involved a collaboration with scientists (primarily Dr. Clifford Watson) at Bruker Instruments, Inc. Using the improved ion injection schemes and differential pumping of... 

Private communication with Dr. Lenian Shen of Bruker Instruments Inc. 

Figure 3.5. (b) Cutaway diagram of the cryostat, showing the essential parts of the magnet and probe. (Courtesy of Bruker Instruments, Inc.)... 

Figure 16.2. A 4.7-T, 30-cm-diameter bore NMR system for animal research. (Courtesy of Bruker Instruments.)...

A direct comparison of the performance characteristics of 1.7 and 3 mm probes has also been reported that is interesting in that it facilitated a subsequent comparison of the performance of the 1.7 and a 1.0 mm probe later developed by Bruker Instruments (see Section 2.3).13,14 Using a 1.0 pmol samples of ibuprofen (4) in both 1.7 and 3 mm NMR tubes, comparative gradient HSQC (gHSQC) exper-... 

Subsequent to reports from the author s laboratory detailing the performance capabilities of the 1.7 mm submicro-probe, Bruker Instruments announced the development of a 1 mm probe, which is presently the smallest volume conventional (sample tube) NMR probe in commercial production. The sample volume of the 1 mm tubes is approximately 5 pL. Curiously, although Bruker reported data using ibuprofen (4) and strychnine (5), as were used in the initial reports on the development of the 1.7 mm submicro-NMR probe,12 13 they reported performance data relative to conventional and cryogenic 5 mm probes, and made no mention of a comparison to 3 or 2.5 mm probes, which would have been a more logical comparison. On this basis, Schlotterbeck and co-workers14 note that with a 1mm tube (5 pL volume for the 1 mm probe and 22 pL fill volume when used in the 5 mm... 

NMR spectrum The proton NMR spectrum of lornoxicam was determined using a Bruker Instrument operating at 500 MHz. The sample was dissolved in DMSO, and all resonance bands were referenced to the... 

NMR spectrum The carbon-13 NMR spectra of lornoxicam were obfained using Bruker instrument operating at 125 MHz and are shown in Figs. 6.12 and 6.13. The sample was dissolved in DMSO and TMS was used as the internal standard. Positions of the various carbons of lornoxicam are shown in Table 6.7. 

FT-ICR-MS systems equipped with external API sources are conunercially available from Bruker Instruments, lonSpec, and Thermo Fimiigan. In order to control the number of ions in the ICR cell, hybrid systems have been developed. Bruker offers a FT-ICR-MS hybrid with a quadrapole front-end (APEX-Qh) [121], whereas the LTQ-FT instrument from Thermo Fimiigan features a linear-ion-trap (LIT, Ch. 2.4.2) front end [122]. In this way, MS-MS can be performed prior to ion introduction into the ICR-cell, avoiding problems with CID in the ICR-cell. 

SFI determinations were conducted according to the official AOCS method at temperatures of 10, 21.1, 26.7, 33.3, and 40°C. SFC was determined by pulsed NMR according to the official AOCS method at the aforementioned temperatures. The instrument was a Bruker Minispec (Bruker Instrument Company, Toronto, Ontario, Canada). 

The first study where the SCS was applied to MRS analysis of prostate biopsies was undertaken at the IBD in Winnipeg.42 Proton MRS (Bruker Instruments, 8.5 T were performed at 37°C on specimens of benign (n = 66) and malignant (n = 21) human prostate tissue specimens collected from transurethral resection of the prostate and radical prostatectomy from 50 patients. Typical spectra of malignant prostate tissue and benign prostate hyperplasia (BPH) are shown in Fig. 5.42 The spectral data were subjected to visual inspection analysis and multivariate analysis, specifically LDA. 

Profile Bruker Instruments was incorporated in 1960 and is headquartered in Germany. Since its founding, the company has diversified into a broad spectrum of analytical techniques and methods in both research and QC/QA applications. These include NMR, FTIR, MRI, MS, and EPR. 

NMR molecular mobility Relaxation times ( H NMR Ti and T2) determination was carried out with a Bruker Avance 300 Spectrometer (Bruker Instruments, Billerica, MA, USA). Samples were packed into 5-mm diameter NMR tubes. Ti was measured using an inversion recovery (Derome, 1987) and T2 with a Carr Purcell Meiboom Gill (CPMG Carr and Purcell, 1954 Meiboom and Gill, 1958) pulse sequences. All data were best fit with mono-exponential relaxation with > 0.99 in all samples. 

Current address U.S. Gypsum Corporation, 700 North Highway 5, Libertyville, IL 60048 Current address Bruker Instrument, Inc., Manning Park, Billercia, MA 01821... 

The NMR spectra on low molecular weight compounds were recorded on a Varian T-60A spectrometer. NMR of polymers were recorded on a JEOL JNM-FX902 Fourier Transform NMR Spectrometer equipped with a FAFT50 FG/BG disc unit, and WM-360 FT NMR spectrometer equipped with ASPEC 2000 computer system manufactured by Bruker Instruments, Inc. 

Polymer Characterization. Molecular weight distributions (MWD s) were obtained from a Waters model 201 ALC/GPC using micro-styragel columns with pore sizes of 500, 10, 10, 10 and 10 A. Calibration was with polystyrene standards in THF solution. Fractionation of bimodal MWD polymers was achieved by use of a Knauer CPC using styragel columns of 10, 10, 10 and 10 A. Tacticity information was obtained from NMR spectra using a 270 MHz Bruker instrument. 

FIGURE 4.15. Simulated 60-, 100-, and 300-MHz spectra of acrylonitrile 300-MHz experimental spectrum (in CDCh) for comparison. For reference to simulation of spectra, see footnote reference to Bruker Instruments program in Section 4.8. 

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