Simplified rotor for fast analyzer of rotary cuvette type

Abstract

A simplified rotor design utilizing two or less cavities per sample analysis station is described. Sample or reagent liquids are statically loaded directly into respective sample analysis cuvettes by means of respective apertures and centripetal ramps communicating with each cuvette. According to one embodiment, a single static loading cavity communicates with each sample analysis cuvette in a conventional manner to facilitate dynamic transfer of liquid from that cavity to the cuvette where mixing of sample and reagent liquids and their photometric analysis take place. Dynamic loading of sample or reagent liquids is provided in another embodiment.

Government Interests

BACKGROUND OF THE INVENTION

The invention described herein relates generally to photometers and more particularly to an improved rotor for fast analyzers of the rotary cuvette type characterized by two or less cavities per sample analysis station. It was made in the course of, or under, a contract with the U.S. Atomic Energy Commission.

Description

The general design and operation of fast analyzers of the rotary cuvette type are generally described in U.S. Pat. No. 3,555,284, issued Jan. 12, 1971, to common assignee in the name of Norman G. Anderson. In the analyzer described in that patent, a central loading disk is provided for statically receiving sample and reagent liquids prior to an analysis operation. An annular array of sample analysis cuvettes is disposed about the central loading disk for receiving the liquids from the loading disk and holding them for photometric analysis. A series of four serially interconnected cavities are required per sampling station: two static loading cavities for receiving sample and reagent liquids, one mixing chamber, and one sample analysis cuvette. Because of space limitations, more recently developed miniaturized fast analyzer designs do not incorporate separate mixing chambers and require only three cavities per sampling station. Typical three-cavity rotor designs are shown in U.S. Pat. No. 3,798,459 issued Mar. 19, 1974, in the name of Anderson, et al., and U.S. Pat. No. 3,795,451, issued Mar. 5, 1974, in the name of Mailen.

The radially innermost static loading cavities which are part of each sampling station limit the total number of sampling stations because of the lack of available rotor space at the smaller radius. In the more recently developed miniaturized fast analyzers identified above, rotors with diameters of 3.5 inches or less are severely limited where three-cavity sampling stations are used.

It is, accordingly, a general object of the invention to provide an improved rotor for a fast photometric analyzer of the rotary cuvette type characterized by a minimum number of cavities per sampling station.

Another, more particular object of the invention is to provide an improved rotor for a fast photometric analyzer of the rotary cuvette type having two or less cavities per sampling station.

SUMMARY OF THE INVENTION

In a fast photometric analyzer of the rotary cuvette type, a simplified rotor design is provided requiring two or less cavities per sampling station. Sample or reagent liquid is loaded directly, by means of a centripetal ramp, into each sample analysis cuvette under static conditions. A single additional static loading cavity is disposed centripetal to each sample analysis cuvette according to one embodiment. Dynamic transfer of liquid from the static loading cavities to respective cuvettes is effected dynamically by conventional means such as radially extending passageways adapted to discharge tangentially into the cuvettes. According to another embodiment, static loading of each cuvette is followed by dynamic loading of a single sample or reagent liquid. Such arrangement permits the greatest number of sample analysis stations for any given size rotor and is especially suitable in miniaturized rotors where space restrictions are greatest.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a rotor made in accordance with the invention.

FIG. 2 is a vertical section view of the rotor of FIG. 1.

FIG. 3 is a top plan view of an alternative rotor design suitable for completely static or static and dynamic loading of sample and reagent liquids.

FIG. 4 is a vertical section view of the rotor of FIG. 3.

FIG. 5 is a bottom plan view of the rotor of FIGS. 3 and 4.

FIG. 6 is a top plan view of an alternative rotor design suitable for combined static and dynamic loading.

FIG. 7 is a vertical section view of the rotor of FIG. 6.

FIG. 8 is a bottom plan view of the rotor of FIGS. 6 and 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, initially to FIGS. 1 and 2, each sampling station 1 (only two of thirty-two shown) is seen to comprise a sample analysis cuvette 2 and a single static loading cavity 3. The rotor 4 is a laminar construction with an opaque mid-section 5 sandwiched between top and bottom transparent plates 6 and 7. As shown, sample analysis cuvettes 2 and static loading cavities 3 are conveniently formed by means of holes or slots in opaque mid-section 5 with plates 6 and 7 providing end closures. Static loading is accomplished by respectively injecting, using a syringe or other suitable means, sample and reagent liquids into the sample analysis cuvettes 2 and cavities 3 under static conditions. Apertures 8 and 9 are provided in top plate 6 to facilitate such loading. A ramp 11 is provided on the centripetal side of each cuvette 2 to permit direct static loading of liquid into the cuvette without incurring spillage during rotation of the rotor. Any liquid retained on the ramp following static loading of cuvette 2 is dynamically transferred to the cuvette upon rotation of the rotor.

Dynamic transfer of liquid from each static loading cavity to a corresponding cuvette 2 occurs through passageway 12 which opens at the top centrifugal side of cavity 3. As shown in FIG. 1, passageway 12 discharges tangentially into cuvette 2 to enhance mixing therein of sample and reagent liquids. A slight outward inclination of each cavity 3 aids in the rapid dynamic transfer of liquids from those cavities. Other conventional means for permitting dynamic transfer of liquid from cavities 3 to cuvettes 2 could be used without departing from the invention such as the capillary passageway and bubble trap described in copending application Ser. No. 354,041 now U.S. Pat. No. 3,795,451, of common assignee.

FIGS. 3, 4, and 5 show an alternative embodiment of the invention in top, vertical section, and bottom views, respectively. Like, though primed, reference numerals are used to designate like features of the alternative rotor embodiment. As in the embodiment of FIGS. 1 and 2, an annular array of sample analysis cuvettes 2' and static loading cavities 3' is provided with passageways 12' joining corresponding cuvettes and cavities. Loading apertures 8' and 9' discharge directly into cuvette 2' and static loading cavity 3' . A dynamic liquid system is also included which may be used where it is desired to perform a multiplicity of tests on a single sample or a single test on a multiplicity of samples, thereby providing a great degree of flexibility to the rotor and making it amenable to virtually any testing situation. Operation of the rotor using static loading only is possible in the manner described above in reference to the embodiment of FIGS. 1 and 2.

The dynamic distribution system includes a central distribution chamber 15 provided with a serrated periphery 16 which causes liquid fed therein while the rotor is spinning to be substantially equally distributed to the cuvettes 2'. Radial passageways 17, which have capillary sized portions 18 to prevent flow from the cuvettes under static conditions, extend between distribution chamber 15 and each cuvette. In operation, either sample or reagent liquids could be statically loaded in the cuvettes, the rotor spun, and respective reagent or sample liquids dynamically injected to mix with the statically loaded liquids. As shown, static loading chamber 3' does not extend completely through opaque mid-section 5 in order that space be available for radial passageways 17.

Another embodiment, limited in use to dynamic loading of sample or reagent liquids, is illustrated in FIGS. 6, 7, and 8. As shown in those figures, an array of sample analysis cuvettes 2" is provided in a manner similar to that of the embodiment of FIGS. 3, 4, and 5. No separate static loading cavities are provided, however, since only one liquid is statically loaded into the cuvettes. A dynamic loading system as described with reference to the embodiment of FIGS. 3, 4, and 5 is provided with like, though double primed, reference numerals designating like features. In operation, sample or reagent is statically loaded in the cuvettes followed by dynamic loading of respective reagent or sample liquid through the dynamic loading system. Rotors made in this manner are limited in number of sample analysis stations only by the number of cuvettes which can be spaced about their peripheries.

The foregoing description of three embodiments of the invention is offered for illustrative purposes only and should not be interpreted in a strictly limiting sense. For example, connecting passageway 12 extending from the top of each static loading cavity 3, 3' may be replaced by a capillary passageway and bubble trap in the manner described in U.S. Pat. No. 3,795,451. It is intended, rather, that the invention be limited only be the scope of the claims attached hereto.

Claims

What is claimed is:

1. An improved rotor for use in a fast photometric analyzer of the rotary cuvette type comprising a disk-shaped member of laminated construction with a central opaque disk sandwiched between top and bottom transparent walls, said disk-shaped member defining:

a, circular array of sample analysis cuvettes extending through said central opaque disk for receiving and holding samples and reagents for photometric analysis;

b. a circular array of outwardly and downwardly extending ramps defining cuvette loading passageways, each of said ramps being in communication with the top end of the centripetal side of a respective cuvette in said array of sample analysis cuvettes;

c. a circular array of first loading apertures extending through said top transparent wall in axial register and liquid communication with respective ramps in said circular array of ramps for facilitating the static loading of liquid in said cuvettes; and

d. means for dynamically injecting liquids into said sample analysis cuvettes.

2. The improved rotor of claim 1 wherein said means for dynamically injecting liquids into said sample analysis cuvettes comprises an array of static loading cavities equal in number and disposed centripetal to said sample analysis cuvettes, second loading apertures extending through said top transparent wall in register with each of said static loading cavities and connecting passageways extending between respective cavities in said array of static loading cavities and said sample analysis cuvettes.

3. The improved rotor of claim 2 wherein said disk-shaped member further defines a central distribution chamber and a plurality of distribution passageways communicating between said distribution chamber and respective cuvettes in said circular array of sample analysis cuvettes.

4. The improvement of claim 3 wherein each of said distribution passageways intersects with adjacent distribution passageways to form a serrated periphery about said distribution chamber.

5. The improvement of claim 3 wherein each of said distribution passageways has a capillary-sized portion.

6. The improved rotor of claim 1 wherein said means for dynamically injecting liquids into said sample analysis cuvettes comprises a central distribution chamber and a plurality of distribution passageways communicating between said distribution chamber and respective cuvettes in said circular array of sample analysis cuvettes.

7. The improved rotor of claim 6 wherein each of said distribution passageways intersects with adjacent distribution passageways to form a serrated periphery about said distribution chamber.

8. The improvement of claim 6 wherein each of said distribution passageways has a capillary-sized portion.