High performance optical absorbance detectors based on low noise switched integrators.
Talanta
; 40(9): 1331-8, 1993 Sep.
Article
em En
| MEDLINE
| ID: mdl-18965786
ABSTRACT
Optical absorption detection is the most common analytical measurement principle in liquid phase analysis. The current state-of-the-art of commercially available detectors exhibit peak-to-peak (p-p) noise levels in the range of 1 x 10(-5)-2 x 10(-5) absorbance units (10-20 microAU). Using circuitry based on newly available switched integrator integrated circuit (IC) packages, it is possible to construct inexpensive absorbance detectors with p-p noise levels as low as 3 microAU under actual use conditions. The necessary electronics are described and performance data are reported with light emitting diodes (LEDs) as light sources. Even in the capillary format with a rectangular capillary (50 x 1000 microm cross section) with a slitwidth <50 microm and with the 1000 microm dimension as the nominal pathlength, p-p noise levels of 10 microAU are observed, from which a concentration limit of detection (LOD) of 10 nM for bromothymol blue (BTB) can be estimated with a 660 nm light source.
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01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Talanta
Ano de publicação:
1993
Tipo de documento:
Article
País de afiliação:
Estados Unidos
País de publicação:
HOLANDA
/
HOLLAND
/
NETHERLANDS
/
NL
/
PAISES BAJOS
/
THE NETHERLANDS