Theta capillary

ESI In-spray solution mixing using theta capillaries Fisher et a/. [97]... 

Figure 4.4 Rapid mixing using theta capillaries [98]. Reprinted with permission from Mortensen, D.N., Williams, E.R. (2014) Theta-Glass Capillaries in Electrospray Ionization Rapid Mixing and Short Droplet Lifetimes. Anal. Chem. 86 9315 9321. Copyright (2014) American Chemical Society...

Fisher, C.M., Kharlamova, A., McLuckey, S.A. (2014) Affecting Protein Charge State Distributions in Nano-electrospray Ionization via In-spray Solution Mixing Using Theta Capillaries. Anal. Chem. 86 4581-4588. 

Modifying the design of the ESI source allows one to reduce the duration of incubation of the reactants prior to the ionization. The continuous flow mixing approach, disclosed by Wilson and Konermann [51], is particularly successful because it enables the duration of reactant incubation to be varied (see Section 4.2.4 and Figure 4.3). Millisecond-scale incubations could readily be accomplished in this way. If even shorter incubations are required, further modification of the standard ESI emitter design may be necessary. Eor example, Fisher et al. [52] used a pulled dual-lumen glass capillary - the so-called theta capillary - as nanoESI emitter for short timescale mixing of protein and acid solutions to... 

In summary, MS has enormous potential for the studies of dynamics of protein folding. Conventional sample preparation and ionization techniques have been optimized considering specifics of such measurements. It appears that rapid micromixers (tees, theta capillary emitters, dual emitters) used with ESI, on-line HDX in conjunction with bottom-up... 

An alternative route to fabrieating SECM-SICM probes with smaller electrode dimensions has been explored by Takahashi and co-workers, who developed a simple proeedure for making dual-barrelled probes from theta capillaries. In this proeess, one of the barrels of a pulled capillary is filled with carbon via the pyrolytic decomposition of a hydrocarbon gas feed. 

Fig. 17 Simultaneous topographical (a) and electrochemical (b) imaging response of neuronal cells achieved using dual-barrelled theta capillary SECM-SICM probes. Electrochemical response reflects the oxidation of 0.5 mM ferrocenemethanol at a tip potential at 0.5 V vs. Ag/AgCl. Reproduced from ref. 158 with permission from Wiley VCH.

For the reactions occurring on the anode, i.e., dissolution, one can expect some limitations due to the acidification and the precipitation of solid phases in ease of saturation of the electrolyte near the tip of the capillary. To avoid this, Lohrengel et al. " proposed a derived set-up consisting of a theta-capillary, i.e., capillaries with two channels separated by a partition wall where an eleetrolyte flows. In this configuration, reaction products like gases (bubbles of O2 or H2) or precipitates eannot block the eapillary. (Fig. 6c). 

The same kind of pH microelectrode can be designed using a working electrode made up a tungsten microelectrode inserted in one channel of a theta capillary (the other channel is similar to the previous sensor and consists in Ag/AgCl reference electrode) (Fig. 

The expression for the capillary rise in Exercise 5.29 assumes that the tube is vertical. How will the expression be modified when the tube is held at an angle 6 (theta) to the vertical ... 

Figure 11.7 X-ray diffraction equipment in capillary configuration showing from left to right Cu x-ray tube, monochromator to select Cu K-alpha radiation, sample mounted in capillary tube, beam tunnel, and X celerator position sensitive detector. The tube and the detector are scanned through a range of angles (theta) by the goniometer (the device in the background on which they are both mounted), and the XRPD is recorded and stored on a computer for subsequent analysis and processing.

X-ray diffraction (XRD) for phase analysis, crystallographic information, residual stress, texture analysis, and reflectometry on powders, bulk, or thin films. Philips X Pert PRO, and a second Philips dual diffractometer system with automated PC control, independent theta/20, sample spinner, and 21 sample changer can be used for crystallography and Rietveld analysis of samples flat, irregular, thin films, or in glass capillaries. 

Double-barrel ISEs fabricated from borosilicate theta glass capillaries with an improved method for better control. 

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