Analytic Advisors
Analytic Advisors

ThermoFisher Scientific (formerly Orion Research, Chelmsford, MA)

 

 

Capillary Electrophoresis Instrumentation Development

Part of the original team which developed the first commercial conductivity detection system for capillary electrophoresis (CE).  Starting from a bread-board setup, the challenge consisted in interfacing a fused-silica separation capillary with a tiny metal electrode  to measure conductivity changes between eluting zones. One of the principal problems was to manage current density phenomena interfering at  the detection electrode in the presence of the high-voltage field. Separation & flow-conditions for anion and cation analysis were established with designing appropriate running electrolytes. The team developed a (patented) open-architecture flow cell which enabled the customer  to replace capillaries and detection elements. The Crystal 1000 CE was introduced in 1994 and was worldwide the first commercially available conductivity detector for CE.

 

Development of a commercial nanotitration instrument

The power of analytical microsystems is illustrated in the development of a proprietary nanotitration chip.   Available functions of the model 6175 PentrodeTM chip were wired to connect an amperometric driving electrode with a pH-sensitive  FET (field effect transistor) function in close vicinity of each other on the chip.  Depending on the driving direction of the current,  a 'cloud' of coulometrically generated hydrogen or hydroxide ions are formed and subsequently consumed by the complementary acidity of  the surrounding bulk solution. This leads to a characteristic titration curve which yields, via calibration and matrix correction,  the total acidity in the solution within seconds(!). The commercially available FLASH titration instrument has the appearance of a  conventional electrode and delivers quantitative data within seconds and without the use of external titrant solutions.

 

List of publications:

 

– Haber, C.; Fairbrother, D.; Soglia, J.; Jones, W. R.; Quantitative Analysis of Small Molecular Weight Ions with Conductivity Detection in Capillary  Electrophoresis, Oral 1367, Pittsburgh Conference, New Orleans, LA 1995.

– Jones, W. R.; Soglia, J.; McGlynn, M.; Haber, C.; Reineck, J.; Krstanovic, C.; Capillary Ion Electrophoresis with Conductivity Detection, Am. Lab. ( Fairfield) 1996, Vol. 28 (5), 25-33.

– Haber, C.; Jones, W. R.; Soglia, J.; Surve, M. A.; McGlynn, M.; Caplan, A.; Reineck, J.; Krstanovic, C.;Conductivity Detection In Capillary Electrophoresis -  A Powerful Tool in Ion Analysis, J. Capillary Electrophor. 1996, 3 (1), 1-11.

– Haber, C.; Electrochemical Detection in Capillary Electrophoresis in Landers, J. P. (Ed.); Handbook of Capillary Electrophoresis, 2nd Ed., CRC Press  (Boca Raton, FL), 1997, pp. 425 - 447.

– Haber, C.; VanSaun, R. J.; Jones, W. R.; Quantitative Analysis of Anions at ppb/ppt Levels with Capillary Electrophoresis and Conductivity Detection:  Enhancement of System Linearity and Precision Using an Internal Standard, Anal. Chem. 1998, 11, 2261-2267.

– West, S. J.; Haber, C.; Capillary Electrophoretic Separation System, US Patent 6159353 (filed April 29, 1998 / issued Dec. 12, 2000); patent describes  electrophoretic separation system on a planar chip of glass or plastic material with on-chip FIA (flow injection analysis) injection and one or multiple  sets of electrodes for electrochemical detection.

 

– West, S. J.; Herdan, J.; Wen, X.; Gillette, T.; Haber, C.; Lipsanopoulos, N.; Yip, J.; Somes, L.; Stevens, J.; Breaux, R.;  Rapid Electrochemical Acid/Base Titrations without Liquid Titrants, Internat. Lab. News, Feb. 2003

 

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© Carsten Haber