Microcapillary injections

Oki, A., Adachi, S., Takamura, Y., Ishihara, K., Kataoka, K., Ichiki, T., Honike, Y., Glucose measurement in blood serum injected by electroosmosis into phospholipid polymer coated microcapillary. Micro Total Analysis Systems, Proceedings of the 4th IJ.TAS Symposium, Enschede, Netherlands, May 14-18, 2000, 403-406. 

FIGURE 9.2. Photographs of a single microdroplet (a) injected into a solution and (b) contacted on a microelectrode by microcapillary manipulation technique. 

LC ESI (8) mass spectra were recorded on a Finnigan TSQ700 instrument (San Jose, CA) in positive ion mode. A sample aliquot was injected into a fused silica microcapillary column with an inside diameter of 100 pm. The microcapillary was filled at the end with 10 cm of a C-18 reversed phase resin. PMP labeled oligosaccharides were eluted at ca. 1 pL/min directly into the electrospray ionization source with a 10 min gradient of acetic acid in H2O (0.5 %, v/v) to 80 % acetonitrile. Determination of experimental molecular weights was done with the deconvolution software provided by the manufacturer. 

The volume that can be injected onto a packed microcapillary or nano-LC column is very limited, e.g., less than 0.1 pi for a 100-pm-lD column. This seriously compromises the achievable concentration detection limits, unless on-column preconcentration would be performed. However, for dilute sample solution, the injection volume is restricted by external peak broadening, and not by column loadability (typically -50-200 pg/g of porous packing material). Therefore, on-line SPE can be applied for sample preconcentration. 

Fig. 5 Determination of the chemotactic sensitivity of E. colt, (a) Schematic of the microfluidic device. Chemoattractant and fluorescein were injected in the microcapillary via inlet C by means of a passive valve, (b) Flow in the main channel (from A to B) was used to transport E. coll past the entrance (M) of the microcapillary, (c, d) Epifluorescence images of the microcapiflary filled with...

Extremely short pulses of a few seconds of extremely small amounts of labeled hormones, injected by means of special microcapillaries, have been used to follow the translocation of lAA during gravitropic stimulation in intact cole-optiles of Avena and Zea (Shaw et al. 1973) movement against gravity of GA3 injected into the lower side of horizontally placed roots and coleoptiles of Zea (Webster and Wilkins 1974) downward and upward dislocation of ABA, microinjected near to the root tip at the upper and lower sides, respectively, in intact horizontal roots of Phaseolus (Hartung 1976 a). 

Lab-on-Chip Devices for Separation-Based Detection, Figure 1 A typical microcapillary electrophoresis system with straight capillary separation channel (1) buffer reservoir, (2) sample reservoir, (3) sample waste reservoir, (4) end waste reservoir, (5) buffer injection channel, (6) sample injection channel, (7) capillary separation channel, (8) injection cross point... 

Figure 10.13. Design of microcapillary electrophoresis chip with electroosmotic sample injection. Detection by laser-induced fluorescence...

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