Precision flow-monitoring spectrometer with low noise and high stability
✍ Scribed by Brian A. Bidlingmeyer; Stanley N. Deming
- Publisher
- Elsevier Science
- Year
- 1971
- Tongue
- English
- Weight
- 313 KB
- Volume
- 43
- Category
- Article
- ISSN
- 0003-2697
No coin nor oath required. For personal study only.
✦ Synopsis
The use of liquid chromatography as an efficient and rapid technique for separation and accurate analysis is clearly in evidence (1,2). The precise and accurate detection of small amounts of separated compounds places stringent requirements upon the detection system used. Short-term noise and baseline drift must be minimal for reliable observation of tiny 'peaks and for accurate integration of peak areas.
Because there is presently no universal detector of high stability and high sensitivity, it is necessary to select a detector that will respond to the characteristics of the specific compounds being separated. Many compounds of interest absorb visible radiation or can be reacted to form compounds that absorb in this region of the spectrum. Thus, in many instances, a visible spectrometer possessing high stability and low noise would be a suitable monitor of the effluent stream from a liquid chromatograph.. Furthermore, it has been pointed out that a single-beam spectrophotometer with % T output will meet the demands for a detector in high-speed liquid chromatography and perform as well as a more sophisticated instrument having a logarithmic amplifier (3).
Pardue and Deming (4) have used optical feedback to modify a Bausch & Lomb Spectronic 20 spectrometer. The resulting instrument possessed high stability and low noise and was capable of continuous wavelength variation between 400 and 625 nm. This report describes a further modification that results in a durable, inexpensive, high-precision, flow-monitoring detector. The limits of detection were determined for the solute methyl orange, as eluted from a chromatographic column using silica gel as an adsorbent.