Sample rotor

The MUX interface uses a dedicated ESI sprayer for each liquid stream. The sprayers are arranged perpendicular to the MS orifice. A sampling rotor within the source cuts parts of the spray... 

Centrifugal evaporator, with 4 to 8 sample rotor compatible with 25ml glass centrifuge tube glassware Rotorvane pump with water trap for centrifugal evaporator SPE 12 port vacuum manifold with vial holder compatible with the vials glassware... 

Fig. 5. Schematic diagram of an eight-channel multiplexed electrospray source. At the current representation, only spray 1 can pass through the sampling rotor to the mass analyzer, whereas sprays 2-8 are blocked. Reprinted with permission from Micromass, UK...

Fig. 23. Schematic representation of the internal components of the Ektachem 700.1 slide storage I, 2 slide delivery, 3 slide storage II, 4 sample dosage unit, 5 reference solution dosage unit, 6 incubator for kinetic measurements, 7 reflectometer for kinetic measurements, 8 diskette drives, 9 reflectometer for colorimetric measurements, 10 incubator for colorimetric measurements, 11 slide rotor, 12 incubator for electrolyte slides, 13 electrometer, 14 sample rotor.

Calibration is effected by means of six calibrators contained in the kits. The relevant graph is stored in the apparatus and is re-plotted whenever the reagent batch is changed or if a technical change is made in the instrument. The sample rotor is filled with 2 vessels each per calibrator. The calibrators consist of a human serum base into which the appropriate calibrator substance has been weighed with the exception of free T4. 

Figure 27 In situ C MAS NMR spectra showing the chemistry of formic acid- C and methanol- C (a-d) and of formic acid-"C and unlabeled methanol (e) on HZSM-5. (a) At 298 K prior to raising the probe temperature (b) after 5 min at 523 K, showing conversion of formic acid to CO (c) after 150 min at 523 K (d) after 210 min at 523 K (e) same as (d) except that unlabeled methanol was used, demonstrating that the label from CO is not incorporated into the hydrocarbon products. Background signals from Kel-F endcaps, which were u.sed to seal the sample rotor, are denoted by brackets.

The 3.5-L reaction chamber of the ultraCLAVE enables processing of several samples (rotors with as many as 50 positions are available) or a single large reaction mixture. Reactions can be scaled from microliters to 3 L under identical conditions using the same reaction system. Continuous, unpulsed delivery of micro-wave power enables the most precise possible control over reaction conditions at millisecond frequencies. 

The geometric term in Equation 4.5 vanishes when =54°44 the magic angle. The dipolar interaction (also referred to as dipolar coupling) should average to zero if the sample is spun at this angle with respect to the static field. However, to completely eliminate the dipolar interactions the speed of rotation must be several times the static linewidth, typically several lOOkHz which is not currently possible. Most commercial MAS systems are capable of rotating 4mm sample rotors at a speed of 10-15 kHz or so. 

Fig. 1 Principle of magic angle spinning (MAS) solid state NMR. (a) Rotation of the sample rotor about the magic angle 9 = 54.7° with respect to the magnetic field Bq, i e-. the space diagonal, (b) Typical solid state NMR spectrum without MAS left hand side, simulated data) and with MAS right hand side). The arrow indicates the isotropic chemical shift Sj o...

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