DRX spectrometer

Two Bruker DRX-spectrometers, each connected to a INDY-workstation (INDY WS) use FTP to communicate and exchange data files via a thin-wire Ethernet with a SUN workstation, acting as a bridge to the central network (thick-wire Ethernet). FTP is used to send data from both DRX spectrometers via the bridge to the central server workstation (SERVER WS). 

The PCs of the system administrator and a few special users have direct access to the DRX-spectrometer.s via the central Server using the FTP protocol. This special group have direct access to any files in the spectrometer s data system, i.e. data files, variou.s lists, pulse programs,... and may transfer files to and from the spectrometers. In addition, they also have the option to create or delete directories, to modify pulse programs and to do other jobs on the spectrometer s data system. As is usual in security sensitive situations, this special group require a password to acces.s the spectrometer. 

Attention With spectra measured on spectrometers equipped with digital filters (DMX, DRX spectrometers), the automatically performed phase correction (DMX Phase Corr.) will be applied twice when the newly created FID is Fourier transformed again. This will introduce the baseline roll characteristic for the data of these type of spectrometers. A first order phase correction must then be performed manually by setting the PHCl value close to -22000 for the data available in the NMR data base. 

Another NMR method was utilized by Cameron et al. [11] to determine rocuronium bromide in its complexed form with y-cyclodextrin. In this method, the experiments were performed at 400 MHz on a Bruker DRX spectrometer at 303 K. The method entailed the use of aH NMR spectra of samples that had been dissolved in D20 at pH 7.5. However, in this report, the authors did not specifically discuss the aH NMR result for rocuronium bromide as single compound. 

The H-NMR spectra of FCC feeds were recorded on a Bruker DRX 400 MHz NMR spectrometer. The concentration of the samples of 5 wt% in CDCI3 was recommended by Molina, Navarro Uribe, and Murgich [2] to avoid concentration dependence of the chemical shift. A 30° pulse sequence was applied, with 4.089 s acquisition time, 2 s pulse delay [2], 8012.8 Hz spectral width, and 64 scans. Hexamethyldisiloxane (HMDSO) was used as a reference. NMR processing was realized using MestReNova software. The phase and baseline of the resulting spectra were manually adjusted and corrected. The spectra were integrated six times and average values were taken for the purpose of calculations. The spectra were divided... 

NMR data on a PC under the MS-WINDOWS environment, e.g WINDOWS 95 or WINDOWS NT. The 2D WIN-NMR program is also linked to the ID WIN-NMR program for special 2D processing. The programs can process data generated on various Bruker NMR spectrometers (AC, AM, CPX, MSL, AMX, ARX, DPX, DRX, DMX,) as well as data produced by one of Bruker s MS-WINDOWS based simulation programs. Furthermore NMR data acquired with spectrometers of other manufacturers (Varian, GE, JEOL) may be converted and processed a.s well. 

All spectra were measured on a Bruker DRX 500 spectrometer, at 500.13MHz ( H) and at 125.76MHz ( C). Sample spinning (20Hz) was used for all ID experiments with the exception of the ID NOE and ID ROESY experiments. As is now common, all 2D experiments were performed with the sample static. All experiments were performed at ambient magnet temperature without any special temperature control. 

NMR data measured on a modern Bruker NMR spectrometer (DMX, DRX, ARX) is stored as a directory in the UXNMR/XWINNMR format. Under the UNIX operating system, data files stored as are themselves directories. 

Figure 6.1 gives an overview of ID and 2D NMR data available for this peracetylated oligosaccharide. The sample was dissolved in CDCl, and all the experiments where measured on a 500 MHz Bruker DRX 500 spectrometer. 

Figure 6.1 UV chromatograms of the test mixture of four / -hydroxybenzoic acid esters (1, methyl 2, ethyl 3, propyl 4, butyl) after the column and after the NMR flow cell at flow rates of (a) 1.0 and (b) 0.1 ml/min conditions column, LiChrospher RP select B, 125 x 4 mm id, 5 Jim, spectrometer, Bruker DRX 600 probe head, 4 mm z-gradient LC probe, active volume 120 a1 eluents, acetonitrile (A) and D2O (B) gradient, t = Omin A/B (40/60), t = 8 min A/B (70/30) at a flow rate of 1.0 ml/min and t = 80 min A/B (70/30) at a flow rate of 0.1 ml/min...

Figure 6.10 Stop-flow NMR spectra of the very early-eluting compounds of the leachate sample the chromatographic conditions are given on the figure. Spectrometer, Bruker DRX 600 probe head, 4 mm z-gradient LC probe between 256 and 1024 scans were acquired...

Figure 6.18 Stop-flow 2D WET-TOCSY spectrum of 3,5-dichloro-2-hydroxybiphenyl. Protons (H4.H6) of the chlorinated ring can be identified due to the magnetization transfer between the signals at 7.23 (H4) and 7.41 (H6) ppm. Conditions spectrometer, Bruker DRX 600 probe head, 4mm z-gradient LC probe. 13C decoupling was applied during the WET-pulse train and acquisition. The spectral size was 8k x 512 data points, with 16 scans per increment, and a 64 ms TOCSY mixing time...

The FI and 13C nuclear magnetic resonance spectra of aspartame are shown in Figures 6 and 7, respectively. These spectra were obtained from a d6-DMSO solution (7.5 mg/mL) using a Bruker Avance DRX-500 spectrometer. All spectra were referenced to tetramethylsilane, and assignments for the H-NMR and 13C-NMR spectra are found in Tables 2 and 3, respectively. 

Characterization. The NMR spectra were recorded on a Bruker DRX 500 spectrometer (500 MHz). The solvent (acetone- ) was used as an internal reference. UV-VIS spectra were recorded on UV-VIS Perkin Elmer Lambda 19 spectrometer. For the estimation of photo cross-linker content at a wavelength of 305 nm, 1 mol% of polymer solution in water was used. 

NMR spectra were recorded, in CDCl with DRX-500MHz spectrometer (TMS as the reference). Size exclusion chromatography (SEC) was performed using a LDC Analytical refractoMonitor IV instrument [RI detector, two columns SDV 8x3(X) (5 pm and 104 A porosity) and SDV 8 x 300 (5 pm and 100 A porosity), eluent - toluene (0.7 ml/min)]. Parallel measurements were effected with Wyatt Optilab 903 apparatus... 

The degree of glycosylation of the glycopolypeptides was estimated via H NMR, MALDI-TOF, and periodate assay (Glycoprotein Carbohydrate Estimation Kit (Pierce, Rockford, IL). H NMR spectra were acquired on a Bruker DRX-400 NMR spectrometer under standard quantitative conditions at 25 °C, and the standard protocols for the periodate assay were as described by the manufacturer. Comparison of sample solutions to a calibration curve of proteins of known carbohydrate content, combined with quantitative amino acid analysis of the samples, permitted estimation of the degree of substitution of the glycopolypeptides. 

NMR spectra were performed on Bruker DRX 400 MHz spectrometer at room temperature. 1 mg/mL solution of the peptide in D2O was prepared and data was collected for 512 scans. 

Fig. 2.5. A comparison of the effect of extractants on solution P nuclear magnetic resonance spectra (Cade-Menun etal., 2002). The samples were a soil and a litter sample collected under stands of cedar in Washington, USA. The NaOH samples were extracted with 0.25 M NaOH, the Chelex samples were extracted with 0.25 M NaOH plus 6 1 Chelex to soil or litter (weight basis) and the EDTA samples were extracted with a 1 1 mix of 0.5 M NaOH plus 0.1 M Na2EDTA. Spectra were collected on a DRX-500 spectrometer with a 10-mm broadband probe, using a 90° pulse, 3.2 s pulse delay and 32°C temperature. See Cade-Menun et al. (2002) for more details.

Values of atom fraction of deuterium in the aqueous nano-droplet was obtained by weighting, in 1 mL volumetric tubes, the appropriate volumes of matched surfactant stock solutions, one containing solubilized (pure) H2O, the other solubilized (pure) D2O. A Bruker DRX-500 NMR spectrometer was used. The spectra were recorded at 25.0 °C, at a digital resolution of 0.06 Hz/data point. The spectrometer probe temperature was periodically monitored, as recommended elsewhere [21] values of 5obs (after 10 min in the sample compartment for thermal equilibration, measured relative to internal TMS) were within the digital resolution limit. 

NMR spectra were obtained by using Bruker Instruments DRX 400 spectrometer. FTIR spectra of samples pressed in KBr disks were measured on an FTS 6000 FTIR spectronwter (Digilab, Cambridge, CT) equipped with a DTGS detector. The absorbance spectra were measured at 4 cm resolution, signal-averaged over 32 scans and baseline corrected. 

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