Liquid waveguide capillary cells

Li, Q. P., Zhang, J. Z., Millero, F. J., and HanseU, D. A. (2005). Continuous colorimetric determination of trace ammonium in seawater with a long-path liquid waveguide capillary cell. Mar. Chem. 96(1-2), 73-85. 

To increase the sensitivity of the analysis, it is recommended that a 5 or 10 cm path length cell be used. The detection Hmit using a 10 cm cell is approximately 0.05 pM, with an upper limit of 40 pM without dilution. Use of a long-path liquid waveguide capillary cell (2 m) lowered the detection hmit to 5 nM with a precision of 5% in the 10—100 nM range (Li et al., 2005). Another approach used to decrease the limit of detection is to preconcentrate the NH4+ prior to analysis. In one technique, the indophenol is concentrated by extraction into n-hexanol this method has a precision of 1.9 nM at concentrations <50 nM (Brzezinski, 1987). The indophenol can also be concentrated onto soHd phase extraction (SPE) octade-cylshane (C18) columns (Selmer and Sorensson, 1986), with the final concentration determined as outlined in Brzezinski (1987). 

L.J. Gimbert, P.J. Worsfold, Environmental applications of liquid-waveguide-capillary cells coupled with spectroscopic detection, Trends Anal. Chem. 26 (2007) 914. 

Because AF Teflon has a lower refractive index than water, it can be used for this purpose. Thus, any light impinging on water will reflect on Teflon walls and the water—Teflon combination will act as an optical fiber. This allows spectrophotometric and fluorimetric cells of along, not necessarily aligned light path, to be constructed such as liquid waveguide capillary cells (LWCCs). 

Underway monitoring of nanomoiar nitrate pius nitrite and phosphate in oligotrophic seawater, (a) Nitrate and nitrite FiA manifoid. (b) Phosphate FiA manifoid. iV injection valve LWCC liquid waveguide capillary cell RC reaction coii. 

L.A. Zimmer, G.A. Cutter, High resolution determination of nanomolar concentrations of dissolved reactive phosphate in ocean surface waters using long path liquid waveguide capillary cells (LWCC) and spectro-metric detection, Liiimol. Oceanogr. Methods 10 (2012) 568-580. 

L.J. Gimbert, P.M. Haygarth, P.J. Worsfold, Determination of nanomolar concentrations of phosphate in natural waters using flow injection with a long path length liquid waveguide capillary cell and soUd-state spectrophotometric detection, Talanta 71 (2007) 1624-1628. 

M.S.A.C. Neves, M.R.S. Souto, I.V. Toth, S.M.A. Victal, M.C. Drumond, A.O.S.S. Rangel, Spectrophotometric flow system using vanadomolybdophosphate detection chemistry and a liquid waveguide capillary cell for the determination of phosphate with improved sensitivity in surface and ground water samples, Talanta 77 (2008) 527-532. 

J. Ma, D. Yuan, M. Zhang, Y. Liang, Reverse flow injection analysis of nanomolar soluble reactive phosphorus in seawater with a long path length liquid waveguide capillary cell and spectrophotometric detection,... 

Pascoa, R. N. M. J., I. V. Toth, and A. O. S. S. Rangel. 2012. Review on recent applications of the liquid waveguide capillary cell in flow based analysis techniques to enhance the sensitivity of spectroscopic detection methods. Anal. Chint. Acta 739 1-13. 

Avivar, J., L. Lerrer, M. Casas, and V. Cerda. 2010. Automated determination of uranium(VI) at ultra trace levels exploiting flow techniques and spectrophotometric detection using a liquid waveguide capillary cell. Anal. Bioanal. Chem. 397 871-878. 

Horstkotte, B., F. Maya, C. M. Duarte, and V. Cerda. 2012b. Determination of ppb-level phenol index using in-syringe dispersive liquid-liquid microextraction and liquid waveguide capillary cell spectrophotometry. Microchim. Acta 179 91-98. 

Zhang, J. Z. (2000). Shipboard automated determination of trace concentrations of nitrite and nitrate in oligotrophic water by gas-segmented continuous flow analysis with a liquid waveguide capillary flow cell. Deep Sea Res. 147, 1157—1171. 

Luminescence core-based optodes have been reported as waveguide capillary flow cells in liquid-filled optical fibers [ 103] or with polymers attached to the inner surface of a glass capillary [104],... 

Kostal, V., Zeisbergerova, M., Urotekova, Z., Slais, K., and Kahle V., Miniaturized liquid core waveguide-based fluorimetric detection cell for capillary separation methods Application in CE of... 

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