U.S. patent number 3,881,872 [Application Number 05/387,965] was granted by the patent office on 1975-05-06 for automatic analyzing device.
This patent grant is currently assigned to Nihon Denshi Kabushiki Kaisha. Invention is credited to Toyohiko Naono.
United States Patent |
3,881,872 |
Naono |
May 6, 1975 |
Automatic analyzing device
Abstract
An analyzing device which automatically and sequentially
analyzes a large number and variety of chemical samples wherein the
system operates with the sample, reagent, and cleaning solution
flow lines pressurized with an inert gas, whereby the formation of
air bubbles in the flow system, oxidation of samples and reagents
and the rise of noxious fumes are prevented.
Inventors: |
Naono; Toyohiko (Akishima,
Tokyo, JA) |
Assignee: |
Nihon Denshi Kabushiki Kaisha
(Tokyo, JA)
|
Family
ID: |
27303677 |
Appl.
No.: |
05/387,965 |
Filed: |
August 13, 1973 |
Foreign Application Priority Data
|
|
|
|
|
Aug 15, 1972 [JA] |
|
|
47-81708 |
Aug 15, 1972 [JA] |
|
|
47-81715 |
Aug 15, 1972 [JA] |
|
|
47-81721 |
|
Current U.S.
Class: |
422/64;
134/22.12; 134/21; 422/81; 134/22.11 |
Current CPC
Class: |
G01N
35/00 (20130101); G01N 2035/1025 (20130101); G01N
35/1079 (20130101) |
Current International
Class: |
G01N
35/00 (20060101); G01N 35/10 (20060101); G01n
001/14 () |
Field of
Search: |
;23/259,253R,23R
;134/22R,21 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Serwin; R. E.
Attorney, Agent or Firm: Webb, Burden, Robinson &
Webb
Claims
Having thus described the invention with detail and particularity
as required by the Patent Laws what is desired protected by Letters
Patent is set forth in the following claims:
1. An apparatus for automatically analyzing a plurality of liquid
samples comprising:
a. a turntable in which sample container tubes are accomodated and
means for intermittently rotating the turntable;
b. a reaction bath composed of a lower chamber associated with
means to maintain it at a constant temperature and an upper chamber
associated with means to pressurize it with inert gas;
c. a plurality of reaction tubes installed in the said reaction
bath vertically positioned in both the upper and lower chambers and
opening into said upper chamber;
d. means for drawing samples to be analyzed from said sample tubes
rotated thereunder by the turntable;
e. means for delivering the sample to said reaction tubes;
f. means for supplying reagents to said reaction tubes by
pressurizing the said reagents with inert gas;
g. means for delivering the contents of the reaction tube through
an opening in the bottom of the reaction tube to an analytical
instrument for detecting; and,
h. means for cleaning the reaction tubes and said analytical
instrument and the instrument delivering means with at least one
kind of cleaning solution, such that all the flow lines comprising
the drawing means, reagent supply means, sample delivery means, and
cleaning means, are isolated from the atmosphere and pressurized
with inert gas at a constant pressure to prevent the oxidation of
solutions, formation of air bubbles, or the rise of noxious
fumes.
2. An apparatus for automatically analyzing a plurality of liquid
samples comprising:
a. a turntable in which sample containing tubes are accomodated and
means for intermittently rotating the turntable;
b. a reaction bath composed of a lower chamber controlled at a
constant temperature and an upper chamber pressurized with inert
gas;
c. a plurality of reaction tubes vertically positioned in said
reaction bath and opening into said upper pressurized chamber;
d. a means for drawing up sample to be analyzed from the said
sample tubes as they are rotated thereunder by the turntable;
e. means for measuring the volume of the sample drawn and
delivering the sample to the reaction tubes;
f. a plurality of reagent selector valves each having a plurality
of inlets in communication with reagent reservoirs and an
outlet;
g. a plurality of reaction tube selector valves connected to said
outlet of one reagent selector valve, each of said reaction tube
selector valves selectively applying reagent to the said reaction
tubes;
h. means for delivering the contents of the reaction tube through
an opening in the bottom of the reaction tube to an analytical
instrument for detecting; and,
i. a cleaning means comprising a plurality of valves each of which
is connected to one reaction tube and an analytical instrument,
said valves having passageways for backwashing at least two kinds
of cleaning solutions to the reaction tube and supplying said
solutions to the analytical instrument and instrument delivering
means and said valves having outlets for draining the cleaning
solutions backwashed into the reaction tube; and,
j. means for supplying at least two kinds of cleaning solutions to
the cleaning means.
3. A device for cleaning the sampling system of an automatic
analyzing apparatus, comprising:
a. a sampler for picking up samples to be analyzed arranged to move
back and forth between a sample tube containing sample and a
cleaning bath;
b. a means for measuring the volume of a sample picked up by said
sampler;
c. a constant flow pump connected to the said measuring means
whereby sample is drawn from the sample tube; and,
d. a means for supplying cleaning solution to the said sample
measuring means and said sampler, the cleaning solution passing
through the said sample measuring means and the said sampler being
fed to said cleaning bath.
4. A reaction device for an automatic analyzing apparatus
comprising a sampler, a reagent supply device, a cleaning device
and an analyzer, said reaction device comprising:
a. a reaction bath composed of a lower chamber and upper chamber
pressurized with inert gas;
b. a plurality of reaction tubes installed in the said reaction
bath within both the upper and lower chambers, the top of each
reaction tube opening into the upper chamber and the lower end of
each reaction tube being in communication through valves with the
analyzer;
c. a means for providing the said lower chamber with a constant
temperature circulating fluid;
d. a means for supplying sample to be treated and reagents to the
said reaction tube; and,
e. a means including said valves for backwashing cleaning solution
into the said reaction tubes such that a part of the cleaning
solution is flushed into the upper chamber of reaction bath and
drained therefrom.
5. An apparatus according to claim 1 in which a buffer tube is
connected to the analyzer exhaust for counteracting the flow
through pressure of the sample so as to position it directly in the
detector and a drain valve connected to said buffer tube for
draining the sample after the sample has been analyzed by said
analyzer.
6. A reaction device according to claim 4 in which a drainage
device for the uppper chamber comprises:
a. a drainage reservoir which is closed from the air, and is
pressurized with inert gas;
b. a pipe which connects the said upper chamber of the reaction
bath and the drainage reservoir whereby backwashed cleaning
solution in the reaction bath may be fed to the said drainage
reservoir through the said pipe;
c. an exhaust pipe for draining off the drains from said drainage
reservoirs;
d. a drainage valve connected to the said exhaust pipe;
e. level gauges for detecting the upper and lower levels of the
drainage in the said drainage reservoir; and,
f. a level detector which operates so as to open and close the said
drainage valve after receiving the signal corresponding to upper
and lower levels of the said drainage in the said drainage
reservoir from said level gauges.
Description
This invention relates to an automatic chemical analyzer suitable
for use in medical laboratories, clinics, pharmacies and the
like.
In the field of chemical and medical analysis, there has been a
growing need to develop an apparatus which automatically and
sequentially analyzes a large number and variety of chemical
samples such as serums with high accuracy and reproducibility.
However, it has been very difficult to design an apparatus having
fully automatic capabilities due to the inherent complicated nature
of the operational system involved. In spite of such difficulties,
however, it is highly desirable to provide a fully integrated
system of automation covering such operations as sequential
sampling, reagent selection, test type selection, reagent tube
selection, flow line washing, etc.; otherwise, sequential analysis
without cross-contamination of the solutions involved becomes
impossible.
According to this invention there is provided an improved apparatus
for automatically and sequentially analyzing a series of liquid
samples, the samples being fractionally divided and diluted by a
suitable diluent or reagent and analyzed by an instrument such as a
colorimeter or flame photometer after the diluted samples have
undergone chemical reaction under specific conditions.
It is an advantage of the automatic analyzer of this invention to
provide for cleaning the reaction tubes and detection flow lines
using different cleaning solutions.
Another advantage of this invention is to provide a novel means for
cleaning the sampling system of the automatic analyzer.
A further advantage of this invention is to provide a unique valve
through which treated liquid samples and cleaning solutions are
periodically and sequentially passed.
Briefly, according to this invention, a sequential multitest system
operates under pressurized closed flow conditions; that is to say,
the sample, reagent and cleaning solution flow lines are
pressurized with a gas such as nitrogen and thus isolated from the
atmosphere. The advantages of this system are as follows: a) Since
the flow lines are under pressure, no air bubbles form in the flow
system. b) Samples and reagents are not oxidized as they are not
exposed to the atmosphere. c) No corrosive or noxious fumes arise.
d) The analytical mechanisms may be comparatively simple and
durable.
The sequential multi-test system according to this invention
permits automatic sequential analysis of multi-constituents in a
single channel. With this system, analysis is carried out while
automatically changing reagents in sequence. Each time a sample is
analyzed, the flow line is cleaned and dried automatically before
proceeding with the analysis of the next sample. All operations
including data recording are carried out automatically by tape
control techniques.
These and other objects of the invention will become apparent by
reading the following detailed description in conjunction with the
accompanying drawings, of which,
FIG. 1 is a diagrammatic illustration of the apparatus constituting
the invention.
FIG. 2 is a partial cross-section of the sample measuring valve in
accordance with this invention. FIG. 3 shows the main parts
constituting the sample measuring valve as shown in FIG. 2.
FIG. 4 is a diagrammatic illustration of the system for cleaning
the sample measuring valve.
FIG. 5 shows the main parts constituting the reaction vessel
selector valve.
FIG. 6 is a partial cross-section and partial break away view of
the reaction bath.
THE OVERALL SYSTEM
Referring now to FIG. 1, there is provided a reaction tube bath 1
in which ten reaction tubes 2-11 are contained. The reaction tube
bath 1 in which the reaction tubes are housed is divided into two
chambers 101 and 102 by sealed plate 100. Upper chamber 101 into
which the reaction tubes open is filled with compressed nitrogen or
another suitable gas supplied from a gas cylinder (not shown) via
regulating valve 103, pressure gauge 104 and pipe 105. The upper
chamber 101 is preferably maintained at a pressure of 1.5 - 3.0
kg/cm.sup.2.
The lower chamber of the reaction tube bath 102 contains water, the
temperature of which is thermostatically controlled by warm water
piped through pipe 108 from water supply unit 107.
Liquid samples are automatically and sequentially fed into the
reaction tubes 2-11 by a reaction tube selection valve 33 so that
up to ten samples, representing for example, as many patients can
be treated in a single measuring sequence.
A sampler comprises a turntable 12 (actually two turntables each
accomodating forty samples) arranged to hold and position sample
holding tubes 13 beneath a pipette 14. A sample is drawn from a
holding tube 13 up through pipette 14 by a constant flow pump 15
and transferred to one of the sample measuring holes 20 provided in
a rotatable member 17 forming a part of the sample measuring valve
16. Constant sample volume is assured as the measuring holes are
precisely machined and are all identical in size. Once the sample
is in the sample measuring hole, rotary slide member 17 rotates by
one tenth of a turn to align with flow line 32 through which a
reagent from a reagent reservoir flows, thereby diluting the
sample. The diluted sample is then delivered to the first reaction
tube 2 via reaction tube selection valve 33. The turntable 12
automatically rotates 9.degree. (360/40) so that the next sample is
positioned below pipette 14. The sampling and diluting procedure is
repeated and the next sample is deposited in the next reaction
tube. In this way, up to ten samples are sequentially transferred
from the sample holding tubes to reaction tubes.
The reaction tube selection valve 33 acts as a selector ensuring
that the first sample enters reaction tube 2, the second sample
enters reaction tube 3, etc. through conduits shown only for
reaction tubes 2 and 3 in FIG. 1. In other words, valve 33 and
sample measuring valve 16 are synchronized and joined by a conduit
34. The valve has ten outlets 35-44 (not all individually numbered
in FIG. 1) each in communication with a different reaction
tube.
Various reagents for example, water, acetic acid, etc. are held in
reagent reservoirs 45-50 contained in a pressurized reagent box 31.
A gas cylinder 51 containing an inert gas, such as nitrogen or
argon, pressurizes the reagent reservoirs and thereby prevents the
generation of air bubbles which would impair measurement accuracy.
A valve 52 regulates the gas pressure. 53 is a pressure gauge. The
reservoirs are pressurized at about 1.5 - 3.0 kg/cm.sup.2.
Reagent selection valves 54-59 (only 54 and 59 are shown in FIG. 1)
are provided with ten inlets a1-a10. Each outlet valve 54-59 has
one numbered 60-65 respectively. Inlets a1-a10 (not all
individually numbered in FIG. 1) of reagent selection valves 54-59
are connected by pipes (not all shown) to reagent reservoirs 45-50
respectively, while outlets 60-65 of the said respective reagent
selection valves 54-59 are connected to the inlet side of the
constant flow pumps 66-71 respectively (not all shown in FIG. 1).
These pumps are controlled by an operation tape control system or
the like so that the volume of reagent to be supplied to the
reaction tubes is increased or decreased according to requirements
by changing the number of pump strokes. The outlets of constant
flow pumps 66-71 are connected to inlets 78-83 of reaction tube
selector valve 72-77 respectively (not all shown). Outlets b1-b10
of the said valves 72-77 are connected through pipes (not all
shown) to the respective reaction tubes 2-11. These valves may be
controlled, for example, by signals optically read from the
operation tape.
Reagent valve 84 forming part of flow line 32 selects the reagent
to be supplied to the sample measuring valve 16 supplied by conduit
85. The selected reagent is drawn through the sample by constant
flow suction pump 86.
The sample reagent or reagents transferred to the reaction tubes
are mixed by motor-driven stirrers 90-99 (not all shown) for a
suitable period, according to the reaction time, prior to being
analyzed.
Reaction tubes 2-11 are connected to reaction tube exhaust flush
control valves (hereafter flush valves) 121-130 (only valves 121
and 130 are shown in FIG. 1) via pipes 109-118 (not all shown
respectively. The flush valves are provided with ports c1-c7. A
rotary slide in said valve is provided with a passageway 131,
through which cleaning solutions may be applied to any one of the
ports through outlet 133. The rotary slide in said valve is also
provided with duct 132, which is joined to the reaction tube and
may communicate with one of the ports. As shown in FIG. 1, outlet
133 and duct 132 always communicate with adjacent ports. Hence,
when duct 132 coincides with port c1, the sample is forced out of
reaction tube 2 by the force of the compressed gas in pressurized
chamber 101 along pipe 109, through duct 132, along pipe 134, and
through inlet d1 of valve 135, prior to entering analyzing
instrument (detector) 137 where the sample is analyzed and an
instrument reading converted into an electrical signal which is
finally recorded by recorder 140. The detector may be a
colorimeter, for example.
Subsequent samples contained in the remaining reaction tubes 3-11
are analyzed and recorded in the same way via valves 122-130 (not
all shown in FIG. 1) and inlets d2-d10 of valve 135, respectively,
detector 137 and recorder 140. A drain valve 139 drains off the
sample after the sample has passed through the analyzing instrument
(detector). A buffer tube 138 counteracts the flow-through pressure
of the sample so as to position it exactly in the detector
cell.
THE CLEANING SYSTEM
The supply source of the cleaning system is contained in three
reservoirs 151, 152, and 153 which are contained in a pressurized
container 150. Reservoir 151 contains acidic or alkaline cleaning
solution, reservoir 152 contains tap water and reservoir 153
contains distilled water.
The cleaning solution of reservoir 151 is drawn up by associated
suction pump 163 through pipe 154 and into inlets c2 of flush
valves 121-130. Also, part of the cleaning solution in this flow
line is channelled through branch pipe 154a and enters circular
passageway 131 of flush valves 121-130 via first rinse valve 155,
second rinse valve 156 and pipe 157.
The tap water in reservoir 152 is similarly drawn up by a second
suction pump 164 through pipe 158 and into inlets c4 of flush
valves 121-130.
Finally, the distilled water in reservoir 153 is pumped through its
designated flow line by associated pump 165 and bifuricated through
pipe 159 so as to feed the liquid into inlets c6 of flush valves
121-130, the remaining portion passing through first rinse valve
155, second rinse valve 156 and pipe 157 and so into circular
passageways 131 of the valves 121-130.
The outlets c3, c5, and c7 of flush valves 121-130 are joined to
exhaust pipe 160, one end of which is exposed to the
atmosphere.
First rinse valve 155 is provided with inlets e1 - e6 and outlet
162. Outlet 162 is in communication with the inlet of second rinse
valve. When the outlet 162 is positioned at f1 and f2, cleaning of
the reaction tubes and detection flow line is halted. A compressed
inert gas of 1.5 - 3.0 kg/cm.sup.2 is supplied to inlets e3 and e6
from a gas tank (not shown) through valve 167 and pressure gauge
168 and conduit 161.
Outlets g1 - 610 (not all numbered in FIG. 1) of second rinse valve
156 are connected to circular passageway 131 of flush valves
121-130, respectively.
With this arrangement, the reaction tubes and the detection flow
line can be washed with different cleaning solutions. When duct 132
of a flush valve 121 is moved from c1 (the sample delivery
position) to c2 position by the intermittent rotation of one eighth
of a turn of the rotary slide of flush valve 121, reaction tube 2
is cleaned with the first cleaning solution. The cleaning solution
of the first reservoir 151 is drawn up by constant flow pump 163,
transmitted to inlet c2 of flush valve 121 and then fed to reaction
tube 2 through duct 132 thereby cleans reaction tube 2. A part of
the cleaning solution flows over from the top of reaction tube 2
and flows to waste reservoir 106 through pipe 166. At this time,
the duct 133 is connected to outlet c1 (see FIG. 3) and hence, the
detection flow line is cleaned with cleaning solution also. To
accomplish this, outlet 162 of first rinse valve 155 is positioned
at inlet e1 or e4. The first cleaning solution is supplied to
circular passageway 131 through rinse valves 155 and 156 and flows
through the detection flow line after passing through outlet
c1.
First rinse selection valve 155 is in turn rotated only one eighth
of a turn in order to change the first cleaning solution to the
third cleaning solution. Outlet 162 connects with inlet e2. Next,
the third cleaning solution drawn up by pump 165 is transferred to
circular passageway 131 through valves 155 and 156 and then fed to
the detection line so as to clean the analytical instrument
(detector) 137. First rinse valve 155 is further rotated one eighth
of a turn; outlet 162 thereby joins inlet e3 to which nitrogen gas
is supplied from the gas tank (not shown). Then the residual
solution in the detection line is blown off with pressurized
nitrogen gas in order to dry the detection line. As a consequence,
the detection line and detector are cleaned and thus do not
contaminate the succeeding sample to be tested by analytical
instrument (detector) 137.
After the detection line has been cleaned, outlet 162 of first
rinse valve 155 is closed at the f2 position until the next sample
(in reaction tube 3) is analyzed by the detector. Flush valve 121
is not rotated until outlet 162 of first rinse valve 155 next moves
to the f2 position. With first rinse valve 155 under the above
condition, flush valve 121 is rotated one eighth of a turn and then
duct 132 and duct 133 are connected to outlets c3 and inlet c2,
respectively. Thus, the first cleaning solution in reaction tube 2
passes through duct 132, then pipe 109 and is finally flushed from
waste pipe 160.
Flush valve 121 is further rotated one eighth of a turn and duct
132 and duct 133 move to the c4 and c3 positions, respectively. The
second cleaning solution drawn up by pump 164 in the second
cleaning solution reservoir 152 is fed to reaction tube 2 through
duct 132, thus the tube is cleaned. Flush valve 121 is then rotated
one eighth of a turn after tube 2 has been cleaned by the second
cleaning solution and then the second cleaning solution is flushed
through outlet c5 and waste pipe 160.
Finally the third cleaning solution is transferred to the reaction
tube 2 through inlet c6 of flush valve 121 and duct 132 and after
that it is flushed from waste pipe 160 through outlet c7 in
accordance with the rotation of flush valve 121.
Thus, the reaction tube is satisfactorily washed with three kinds
of cleaning solutions after completion of each analysis, and
finally, the residual solution is blown off with pressurized
nitrogen gas supplied to chamber 101 to dry the reaction tube.
All of these operations may be automatically carried out by the
operation tape. Furthermore, with this invention it is possible to
wash two empty reaction tubes with cleaning solutions at the same
time the samples are being analyzed.
REACTION BATH CONTROL
The reaction tube bath 1 already described has associated therewith
a drainage reservoir 106 which is closed and pressurized at 1.5 -
3.0 kg/cm.sup.2 with nitrogen gas supplied from the gas tank (not
shown) through branch pipe 105a. This reservoir is equipped with
two level gauges 170, which are used to detect the upper and lower
levels of the drainage in order to keep the pressure drainage
reservoir 106 constant. Level gauges 170 are connected to level
detector 171 which operates drain valve 173 after receiving a
signal from level gauges 170. When the cleaning solution is fed
from pressurized chamber 101 to drainage reservoir 106, the
drainage level goes up and upper level gauge 170 detects it; the
level detector 171 operates so as to open valve 173. By opening
valve 173, some of the drainage is flushed from valve 173 through
drainage pipe 172 since the drainage is pressurized. Thus, the
pressure in drainage reservoir 106 drops. In order to minimize
fluctuations in pressure, the level gauges are placed close to each
other.
As is explained hereinabove, the system according to this invention
allows automatic sequential analysis of multiconstituents by means
of a single channel. With this system analysis is carried out while
automatically changing reagents in sequence. Each time a sample is
analyzed, the flow line is cleaned and dried automatically, and
then analysis proceeds to the next sample.
VALVE ASSEMBLY
FIG. 2 shows a cross-section of the novel sample measuring valve 16
used in FIG. 1. The same numerals used in each drawing indicate the
same elements.
Rotatable slide 17 is arranged axially between the upper and lower
fixed member 18 and 19 so as to contact each of them. These members
are made of polytetrafluoroethylene resin, borosilicate glass, or
ruby, whereby the said members are resistant to corrosion by
reagents and solvents. Upper fixed member 18 is supported by a
cylindrical casing 180 positioned thereabout having conical hole
181 on its upper surface near the axis in which steel ball 182 is
positioned. Casing 183 is threaded on to upper base plate 184 in
order to bias the said steel ball 182 by means of rod 185 against
casing 180. Spring 186 urges the said rod 185 against ball 182.
Casing 180 is secured to plate 184 by screw 187 to prevent rotating
thereof. Fitting 188 is secured to casing 180 and is used to make
the pipe connection with the passageway of upper member 18. Lower
fixed member 19 is supported by cylindrical casing 189 and 190
which are secured to lower base plate 191 by means of screws
192.
A cylindrical casing is provided to support rotatable slide member
17. Bushings 194 and 195 made of a material resistant to such
corroding reagents and solvents are disposed between casing 180 and
casing 193 and between casing 189 and casing 193 so as to provide a
smooth rotation of member 17. Cylinder 193 is fixed to a Geneva
gear 196 which is in working contact with roller 197. Shaft 198
which is secured to base plates 184 and 191 is provided with bevel
gear 199 and arm 200 that supports the said roller 197. The said
bevel gear 199 is meshed with bevel gear 201 which is secured to
shaft 202 of motor 203. By driving motor 203, Geneva gear 196 is
intermittently rotated through gears 201 and 199 and roller 197,
thus, passageway 20 provided in a rotatable member 17 is
positioned. Motor 203 is intermittently activated by a limit
switch.
SAMPLE MEASURING VALVE
In FIG. 3 rotary members and fixed members used in sample measuring
valve 16 are shown. They would be supported by a suitable valve
assembly explained with reference to FIG. 2. Rotatable member 17
has ten measuring holes 211-220 which are provided along the
periphery thereof. These holes are accurately fabricated so that
their volumes are the same. Upper fixed member 18 has two
passageways 221 and 222, which are joined to constant flow pumps 86
and 15, respectively (see FIG. 1). Lower fixed member 19 is
provided with passageways 223 and 224, the former being connected
to reaction tube selection valve 33 and the latter to pipette 14
(see FIG. 1). The liquid sample to be analyzed is introduced into
one of the measuring holes, for example, hole 218, through
passageway 224. After the liquid sample is measured by the
measuring hole, rotatable member 17 is rotated one tenth of a turn
in the direction of the arrow and measuring hole 218 is is
connected to passageways 221 and 223. Then the reagent supplied
from the reagent tank is fed to passageway 221 so as to transmit
the measured sample to the reaction tube through outlet 223.
At the same time, the next sample measuring hole 217 is washed as
explained hereafter, by the cleaning solution which is fed from the
cleaning solution tank to passageway 222; thereafter, the sample is
measured by measuring hole 217.
CLEANING SYSTEM FOR MEASURING VALVE
FIG. 4 schematically illustrates the cleaning system of the sample
measuring valve. In order to wash, sample measuring valve 16 and
pipette 14, three kinds of cleaning solutions are provided, each of
which is drawn up in sequence by constant flow pump 15. One end of
pump 15 is connected to needle valve 233 comprising block 234 and
plungers 235-238. Plungers 236-238 are connected to closed vessels
239, 240 and 241 through pipes 242, 243, and 244 respectively.
These pressured vessels are pressurized with nitrogen gas. The
first cleaning solution such as acid solution in the first tank 245
is drawn up and transmitted to vessel 239 by pump 246. Water is
transferred from the second tank 247 into closed vessel 240 by pump
248. Also, distilled water in the third tank 249 is fed to vessel
241, by pump 250. Constant pressure valves 251, 252, and 253 are
utilized so that when the pressure in the closed vessels becomes
higher than the preset value, the valves are opened. Then the
cleaning solution in the closed vessel is fed back to the cleaning
solution tank.
Pressure gauges 254, 255 and 256 indicate the pressure of closed
vessels 239, 240 and 241.
With this arrangement, when plunger 236 moves downward, pipes 242
and 257 come on line, and the cleaning solution in closed vessel
239 which is being pressurized with nitrogen gas, is transferred
into needle valve 233 and in turn delivered to cleaning bath 231
after passing through sample measuring valve 16 and pipette 14. The
second cleaning solution reserved in closed vessel 240, then is
flushed through sample measuring valve 16 and pipette 14 to clean
them after plunger 236 moves upward and plunger 237 downward.
Furthermore, in the same manner as the first and second cleaning
solutions, the third cleaning solution in closed vessel 241 is used
for cleaning valve 16 and pipette 14.
Thus, the sampling system including measuring valve 16 and pipette
14 is satisfactorily washed with three kinds of solutions to avoid
cross-contamination. Cleaning is carried out after the sample is
measured by sample measuring valve 16 and then transferred to the
reaction tube. After termination of cleaning, pipette 14 is moved
to the position indicated by the dotted lines and plunger 235 and
pump 15 are operated so as to pick up the next sample to be
analyzed for measurement by sample measuring valve 16. After that,
constant flow pump 15 is stopped and the sample measuring valve 16
is rotated one tenth of a turn; thus, the measured sample is
supplied to the reaction tube with reagent transferred from reagent
box 31 (see FIG. 1) into valve 16 through pipe 32. All these
operations may be carried out automatically by the operation
control tape.
FLUSH VALVE
FIG. 5 shows a perspective view of the main components of valve 121
in FIG. 1, in which rotary slide 261, and upper and lower fixed
members 262 and 263 are illustrated. These components which are
made of polytetrafluoroethylene resin or ruby are arranged in the
valve assembly in the same manner as explained with reference in
FIG. 2. Rotary slide 261 is provided with duct 133 and slanted duct
132 which is radially spaced from hole 133 one eighth of a turn
therefrom. Upper fixed member 262 is provided with circular
passageway 131 on one surface thereof and ducts 109 and 157. One
end of duct 109 is extended to the center of the surface of member
262 and is joined to the end of slanted duct 132 of rotary slide
261; the other end of passageway 109 is connected to reaction tube
2. One end of duct 157 is connected to valve 156 and the other end
is connected to circular passageway 131. Outlet ports c1 - c7 are
provided in the lower member radially spaced along the periphery
thereof, but at one position, c8, no port is provided. By
contacting rotary slide 261 with the upper and lower member 262 and
263, duct 133 is connected to circular passageway 131 and one of
the ports, for example c7; duct 132 is connected to duct 109 and
one of the ports, for example, c6. When the slanted duct 132 is at
the c8 (closed) position, the sample is treated in the reaction
tube 2.
REACTION BATH
FIG. 6 shows a partial cross-section of the reaction bath utilized
for reaction of the sample to be analyzed. Reaction tube 2 whose
upper end is open and lower end is conically shaped, is installed
in reaction bath 1. The reaction bath is basically formed by plates
271, 272, 273 and 274 defining an enclosure divided into two
compartments, namely, pressurized chamber 101 which is pressurized
with nitrogen gas, and water bath 102 by divider plate 100 as
already described. The reaction process is directly observed
through observation window 275 (also defining the enclosure)
secured to the divider plate 100 and plate 273. The lower end of
reaction tube 2 having flange 276 is supported by bracket member
277 which is secured to yoke 273 by screws 278. The reaction tube 2
is sealed to the bottom plate 273 and the bracket member 277 by
O-rings 279.
Pipe 109 is connected to the hole 290 provided at the end of
reaction tube 2 by means of fixture 280 secured to member 277.
Support bracket 281 which is secured to plate 100 by screws 282 and
has opening 283 from which cleaning solution may be flushed
supports reaction tube 2. Pipes 284 and 285 held by fixtures 287
and 288 are extended onto reaction tube 2 and supply liquid sample
and reagent to it. The end of pipes 284 and 285 are cut at a slant.
Stirrer 90 is rotated by a motor (not shown) which drives belt 289
in order to improve the homogeneity of the reaction solution and
the reproducibility of the reaction.
All of the required operation, from the supplying of samples to the
recording of data may be carried out through the operation control
tape. Connected on-line with a computer this apparatus may provide
digital readout valves from both the specified format and the
analog indication form.
* * * * *