Note: Descriptions are shown in the official language in which they were submitted.
so
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The invention relates to an analytical means or
the de section of ingredients ox aqueous or water-containing
fluids .
In analytical screening methods, a pronounced
5 trend to the use of quick tests based on srr,al:L test rods,
which are understood as esserltially two-dimensional struck
lures, such as test strips, has been noticeable for a
number of years . However, toes t strips enclosed by a
film or structures in the shape ox small tubes are also
10 Icnown German AuslegeschriIt 1,498,875 and German
O~fenlegungsschrift 1,940,964). These Buick tests
are applied either by immersion OX an absorbent material,
for example paper, which is impregnated with the chemicals
necessary for the -test, into the sample to be examined
15 and observation of any color reaction which may occur,
or by immersion OX a par-t OX the paper impregnated with
. chemicals, chromatographic absorption ox the sample and
observation of a color change in the non-~mmersed part
OX the paper.
I Chromatographic quick tests of the last mentioned
type are in general used. when before, during or after -the
redaction of the chemicals necessary for the test with the
substance to be detected it its intended to obtain a
. separation of the substance to be detected from other sub-
25 stances present in the sample, the reaction products of
the chemicals necessary for the lo it, or various reagents
from one another
I'll essential precondition for fault-free, lopper-
educible functioning of chronl.a~o~raph.ic quick tests is auniforin
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chromatographic saturation of that par, of -the
absorbent material which has not been immersed, and to s
in turn is achieved by making fluid available uniformly
d reproducibly at a precisely defined starting line of
the chromatographically active material.
US. Patent Specifications and 3,91~,647
have disclosed a quick-test device josh comprises a
chromatographically active material and a sample vessel
rigidly connected thereto, the sample vessel communicating
lo with the absorbent material via fluid-permeable orifices.
The manufacture of this quick-test device is
expensive, and the test strip must always be held Yen-
tidally after immersion. Moreover, since fluid is
sucked into the chroma-tographically active material, the
fluid level in the reservoir falls and -the starting line
ox the chroma-togram thus continuously changes during
the test, and this leads to considerable fluctuations
in the length of time taken for chromatography.
According to German Offenlegungsschrift 2,215,089,
the chroma-togra.phically active rrlateriai it joined to a
layer of a syllable gel former which serves as a fluid
re~.crvoir,
This process leads to a product winch, in the
mois-tstate,i.s very unstable mechanically and readily
becomes smear and, additionally, the gel itself strongly
retains the moisture and -the swelling process is slow.
.. None ox these analytical wryness meet the demands
which must be made on a chromato~raphi.c quickest device,
namely simple handling, intensive mamlfac-ture without
us
problems and reproducible chromatographic proper-ties
(sleight of development, time ox development due -to curl-
slant availability of fluids
It was therefore the object OX the invention to
combine these demands in an improved cryptographic
quickest device, comprising chromatographically acid
material in the fluid reservoir, with reproducible Abe
sorption ox` fluid.
Surprisingly, it has now been found that porous
it hydrophilic, non~gel-forming syllable polymer are
outstandingly suitable, even if the pore structure is
non-uniform and coarse, as self~drawin~ fluid reservoirs
with a very high and uniform absorption and release of
fluid in a chromatographic quick-test device.
The preparation of porous hydroph~lic, syllable
polymers is described, for example in German Offenlegungs-
shrift 2,739,008 and 2,722,025, page 8 and 9.
Accordingly, examples of suitable polymeric sub-
stances ox hydrophilic nature are regenerated and modified
types of cellulose, which may be chemically cross linked,
w~ter-insoluble graft polymers of cellulose and synthetic
hydrophilic polymer--~ormers, such as polyacrylamides,
polyacrylic acids, polyglycols and polyvinyl pyrrolidones,
as well as these synthetic polymer-~ormers alone in a
I cross linked form.
Regenerated, modified and/or crosslil~ed types
cellulose are preferred.
The c~Jnsid~rable swelling capacity in aqueous
media proves to be very advan-cageolls o'er purposes of the
TV
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inv~ntiorl, A dry sponge of these polymers con, for
example, be compressed to 1/10 of its ret vole byway
simple pressing step, and it retains this form until it
is moistener. Not only -two dimensional, paper-like
structures but also powders 9 flakes or other shaped
structures can be used for this purpose. A dry-
pressed two-dimensional material of the same dry strength
as the chromatographically active material used can ad
vantageously be employed for the preparation of test
strips 9 since the least difficulties are then to be ox-
pealed in production engineering.
Papers ox cellulose or cellulose derivatives as
well as coated silica gels suitable for chromatography,
and the like can be used as the chromatographically active
material.
The examples which follow are intended to explain
the invention:
to 1: Test s-trip for the de-termination of alpha
aimless in urine
A 10 mm long, 7 mm wide and 0.2 morn -thick piece
ox dry-press~d artificial sponge ox regenerated cell-
love is glued to one end of a plastic film ox 0.3 mm
thickness, 7 mm width and 10 am length. Adjoining the
wormer, a piece of filter paper of 40 mm length, 7 mm
width and 0.2 mm thickness is glued on. One or several
streaks of water-insoluble chromogenic starch compound
ar~a~plied to the paper 5 transversely to the direction of
the test strip.
To carry out the test, the lower third ox that
erred of the test strip to which the artificial sponge is
' glued is immersed in urine ' '120 I of urine
are sucked up by the artificial sponge, with e~pansicn
to approximately ten times the thickness, and are trays-
ported onwards to the joint edge with the filter paperweight this edge, the chromatography process s arts after
about 2 seconds, and it is finished after about 5 minutes.
The aimless content can bread offsemi-cuantita-tivel~J from
number of the starch streakswhicn have been detached'
during these 5 minutes.
' In other embodiments, the sponge itself can
'- already contain cherrlicals or other substances (for example
enzymes) necessary for the test, the fluid absorption
''''capacity decreasing slightly. '' '"''-'
Another technically utilizable property of the
artificial sponge results from the fact that the pressed
sponge is only syllable with water and can thus also be
sod in an optimum manner in effluents which are severely
contaminated with organic matter, without the fluid Abe -
.0 sorption capacity already being saturated by non-aqueous
solvents.
Exarn~le 2: Test for iron content in effluent (see drawing)
,, _
' A small plastic tube (1) (Makrolon(R)) having an
internal diameter of 6 mm is closed at one end lath a
~ater-permeable perforated plate (2j, and it is then
filled with about 1 ml of a loose bed of a powder I of
venerated cellulose of a particle size of about 1 2 mm
d~alne~er, and the bed is compacted to 1 ml (= 3 CDI lent
ox Thea small tube with the rid of a paper stopper (4)
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inserted afterwards. above the latter, a paper sleeve
(5) having an external dimwit of 6 mm and impregnated
with potassium hexacyanoferrate-~I)is arranged and this
is pressed against the paper stopper (4) with the aid of
a closure plug (6).
. To carry out the test, the small tube Ruth the
water permeable perforated plate is immersed for about
6 seconds into the effluent sample. The defined qua-
lily of fluid absorbed within this period migrates into
the paper sleeve (5) where sparingly soluble Prussian
Blue is formed WriteNow Fe-tLII)salts, When chromatography
is complete, the concentration of Fissility in the
effluent sample can be read off from the height of the
Prussian Blue zone in the paper sleeve (5) by reference
Lo to the calibration curve.
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