US5900934A
Expired / Lapsed
US
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Capillary chromatography detector apparatus
Assignee: Waters Technologies Corp
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Filing: 1997-10-06
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Granted: 1999-05-04
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Expires: 2017-10-06
Abstract
Abstract An apparatus to effect multiple simultaneous separations to measure absorbance, comprising a photodetector array comprising a plurality of photosensitive elements connected to provide a serial output. The elements are typically pixels of a photodiode array (PDA). The elements are illuminated by a light source positioned to illuminate at least a portion of the photodetector array. The light source may be a an AC or DC mercury lamp or other useable light source for chromatography. An array of separation channels is disposed between the light source and the photodetector array, each of the separation channels having a lumen, a sample introduction end and a detection region disposed opposite the sample introduction end. Typically and as disclosed herein the array is a multiple parallel capillary electrophoresis system. The last element is a mask element having at least one aperture for each associated separation channel, each aperture corresponding to its associated separation channel thereby selectively permitting light from the light source to pass through the lumen of its associated separation channel, at least a portion of the light passing through the lumen of the associated separation channel falling on a respective photosensitive element of the photodetector array to effect measurement of absorption of light by a sample introduced into the sample introduction end of the associated separation channel. Also disclosed is an instrument for analyzing the spectral content of chemical samples contained in a large number of capillary tubes which uses a single AC powered light source (which therefore gives a time-varying light output) and a single self-scanned PDA detector. This greatly reduces the number of circuit elements required, since only one amplifier, one A/D converter, one light source and one detector need be provided. The resulting device can be constructed less expensively and take up less space as compared to the conventional system. Further, a control signal having a particular frequency is supplied to both the power supply of the AC light source and the PDA detector. This stabilizes the detector signal's baseline.
Inventors
- 👤 Anthony C. Gilby
- 👤 William W. Carson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:59
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/447; G01N27/44704; G01N27/44717; G01N27/44721; G01N27/44756; G01N27/44782; G01N30/00; G01N30/02; G01N30/62; G01N30/74
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
110 words
A chemical sample analysis apparatus comprising: an AC light source; an AC power supply connected to said AC light source; a photodetector array; a detector scanning clock controlling said photodetector array, said AC power supply and said detector scanning clock being phase locked to each other by one of, said AC power supply being substantially equal in frequency to said detector scanning clock, or one of said detector scanning clock and said AC power supply being a fixed multiple of the other of said detector scanning clock and said AC power supply; and means to hold an array of samples disposed between said AC light source and said photodetector array.
Claim 2
Dependent Claim
110 words
A chemical sample analysis apparatus comprising: an AC light source; an AC power supply connected to said AC light source; a photodetector array; a detector scanning clock controlling said photodetector array, said AC power supply and said detector scanning clock being phase locked to each other by one of, said AC power supply being substantially equal in frequency to said detector scanning clock, or one of said detector scanning clock and said AC power supply being a fixed multiple of the other of said detector scanning clock and said AC power supply; and means to hold an array of samples disposed between said AC light source and said photodetector array.
Claim 3
Dependent Claim
28 words
The apparatus of claim 1 wherein said photodetector array is made up of a plurality of photosensitive elements connected to a serial output line of said photodetector array.
Claim 4
Dependent Claim
23 words
The apparatus of claim 2 further comprising an amplifier and an A/D converter connected to said serial output line of said photodetector array.
Claim 5
Dependent Claim
15 words
The apparatus of claim 1 wherein said array of samples are contained in capillary tubes.
Claim 6
Dependent Claim
45 words
The apparatus of claim 1 wherein said array of samples is configured in an array of capillary tubes including a mask portion which substantially blocks light from said light source, which light has not passed through said array of samples, from reaching said photodetector array.
Claim 7
Dependent Claim
32 words
The apparatus of claim 1 further including a filter disposed between said AC light source and said photodetector array, for selecting at least one wavelength of light from said AC light source.
Claim 8
Dependent Claim
28 words
The apparatus of claim 1 further including optics to focus said light from said AC light source to impinge upon said array of samples in a predetermined manner.
Claim 9
Dependent Claim
16 words
The apparatus of claim 1 wherein said array of samples includes at least one reference channel.
Claim 10
Dependent Claim
18 words
The apparatus of claim 8 wherein said at least one reference channel includes a length of optical fiber.
Claim 11
Independent Claim
250 words
An apparatus for determining the presence or absence of an analyte comprising: a) means for holding a containment vessel, said containment vessel for containing a sample in which the analyte may be present or absent; b) a light source capable of producing pulsed light when powered by an alternating current, said light source in communication with said containment vessel, said alternating current having a frequency which causes light to be at said frequency or multiple of said frequency; c) a photodetector array having one or more pixels in optical communication with said containment vessel and said light source, for receiving light from said light source through said containment vessel and the sample contained therein, said photodetector array having a scanning frequency in which electrical discharge signals are received from said pixels; and d) a clock control for controlling the frequency of at least one of the frequencies of said scanning frequency and said alternating current frequency such that at least one frequency is a multiple of the other or said frequencies are equal, said photodetector array receiving light from said light source through said containment vessel and sample contained therein to measure absorbance over a period of time comprising a plurality of electrical discharge signals, said pixels are scanned at a frequency corresponding the frequency of said alternating current and said electrical discharge signals generated at constant light intensity to reduce baseline variability of said electrical discharge signals over a period of time comprising a plurality of electrical discharge signals.
Claim 12
Independent Claim
250 words
An apparatus for determining the presence or absence of an analyte comprising: a) means for holding a containment vessel, said containment vessel for containing a sample in which the analyte may be present or absent; b) a light source capable of producing pulsed light when powered by an alternating current, said light source in communication with said containment vessel, said alternating current having a frequency which causes light to be at said frequency or multiple of said frequency; c) a photodetector array having one or more pixels in optical communication with said containment vessel and said light source, for receiving light from said light source through said containment vessel and the sample contained therein, said photodetector array having a scanning frequency in which electrical discharge signals are received from said pixels; and d) a clock control for controlling the frequency of at least one of the frequencies of said scanning frequency and said alternating current frequency such that at least one frequency is a multiple of the other or said frequencies are equal, said photodetector array receiving light from said light source through said containment vessel and sample contained therein to measure absorbance over a period of time comprising a plurality of electrical discharge signals, said pixels are scanned at a frequency corresponding the frequency of said alternating current and said electrical discharge signals generated at constant light intensity to reduce baseline variability of said electrical discharge signals over a period of time comprising a plurality of electrical discharge signals.
Claim 13
Independent Claim
180 words
An apparatus for determining the presence or absence of an analyte, in a plurality of samples, each sample held in separate separation channels, comprising: a) a planar housing having a plurality of separation channels, each separation channel having a lumen for containing a sample in which the analyte may be present or absent, said planar housing having a mask element having one or more optical openings associated with each separation channel to selectively allow light from a light source to pass through said lumen; b) a light source capable of producing light, said light source in communication with the lumen of each separation channel through said one or more optical openings of said mask element; c) a photodetector array having one or more pixels in optical communication with the lumen of said separation channel and said light source, for receiving light from said light source through the lumen of said separation channel and the sample contained therein, said photodetector array producing electrical discharge signals serially from said pixels with are related to the absorbance of light by the sample therein.
Claim 14
Independent Claim
180 words
An apparatus for determining the presence or absence of an analyte, in a plurality of samples, each sample held in separate separation channels, comprising: a) a planar housing having a plurality of separation channels, each separation channel having a lumen for containing a sample in which the analyte may be present or absent, said planar housing having a mask element having one or more optical openings associated with each separation channel to selectively allow light from a light source to pass through said lumen; b) a light source capable of producing light, said light source in communication with the lumen of each separation channel through said one or more optical openings of said mask element; c) a photodetector array having one or more pixels in optical communication with the lumen of said separation channel and said light source, for receiving light from said light source through the lumen of said separation channel and the sample contained therein, said photodetector array producing electrical discharge signals serially from said pixels with are related to the absorbance of light by the sample therein.
Claim 15
Dependent Claim
32 words
The apparatus of claim 11 wherein said apparatus further includes a signal processor receiving said serial-output and computing absorbance as a function of the measurement of absorption of light by said sample.
Claim 16
Dependent Claim
15 words
The apparatus of claim 11 wherein said separation channels are etched into a planar substrate.
Claim 17
Dependent Claim
14 words
The apparatus of claim 11 wherein said separation channels are implemented as separation capillaries.
Claim 18
Dependent Claim
14 words
The apparatus of claim 11 wherein said photodetector array is a self-scanned photodiode array.
Claim 19
Dependent Claim
31 words
The apparatus of claim 11 wherein said light source is powered by an AC power supply and said photodetector array is a self-scanned photodiode array driven by a detector scanning clock.
Claim 20
Dependent Claim
67 words
The apparatus of claim 16 wherein said AC power supply and said detector scanning clock are phase locked to each other by one of, said AC power supply being substantially equal in frequency to said detector scanning clock, or one of said detector scanning clock and said AC power supply being a fixed multiple of the other of said detector scanning clock and said AC power supply.
Claim 21
Dependent Claim
19 words
The apparatus of claim 11 further including a wavelength filter disposed between said light source and said photodetector array.
Claim 22
Dependent Claim
27 words
The apparatus of claim 11 wherein said array of separation channels includes at least one reference channel, free of sample, interspersed among said array of separation channels.
Claim 23
Dependent Claim
18 words
The apparatus of claim 11 wherein said at least one reference channel includes a length of optical fiber.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-05-03 | 2002-11-02 | 2003-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-05-03 | 2006-11-02 | 2007-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-05-03 | 2010-11-02 | 2011-05-04 | $7700.00 | Window Closed / Lapsed |