US3778384A - Diagnostic composition for the quantitative determination of glucose - Google Patents
Diagnostic composition for the quantitative determination of glucose Download PDFInfo
- Publication number
- US3778384A US3778384A US00275926A US3778384DA US3778384A US 3778384 A US3778384 A US 3778384A US 00275926 A US00275926 A US 00275926A US 3778384D A US3778384D A US 3778384DA US 3778384 A US3778384 A US 3778384A
- Authority
- US
- United States
- Prior art keywords
- glucose
- toluidine
- sodium
- test
- orthoarsenate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 title abstract description 23
- 239000008103 glucose Substances 0.000 title abstract description 23
- 239000000203 mixture Substances 0.000 title abstract description 19
- RNVCVTLRINQCPJ-UHFFFAOYSA-N o-toluidine Chemical compound CC1=CC=CC=C1N RNVCVTLRINQCPJ-UHFFFAOYSA-N 0.000 abstract description 51
- 239000003153 chemical reaction reagent Substances 0.000 abstract description 17
- 150000001495 arsenic compounds Chemical class 0.000 abstract description 10
- 239000013060 biological fluid Substances 0.000 abstract description 6
- 239000011734 sodium Substances 0.000 description 26
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 23
- UMGDCJDMYOKAJW-UHFFFAOYSA-N thiourea Chemical compound NC(N)=S UMGDCJDMYOKAJW-UHFFFAOYSA-N 0.000 description 14
- 238000012360 testing method Methods 0.000 description 13
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 11
- GOLCXWYRSKYTSP-UHFFFAOYSA-N arsenic trioxide Inorganic materials O1[As]2O[As]1O2 GOLCXWYRSKYTSP-UHFFFAOYSA-N 0.000 description 11
- 229910052708 sodium Inorganic materials 0.000 description 11
- 229960000583 acetic acid Drugs 0.000 description 10
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 125000000223 arsonoyl group Chemical group [H][As](*)(*)=O 0.000 description 8
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Natural products NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 7
- 239000012362 glacial acetic acid Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 230000035945 sensitivity Effects 0.000 description 7
- COHDHYZHOPQOFD-UHFFFAOYSA-N arsenic pentoxide Chemical compound O=[As](=O)O[As](=O)=O COHDHYZHOPQOFD-UHFFFAOYSA-N 0.000 description 6
- 210000004369 blood Anatomy 0.000 description 6
- 239000008280 blood Substances 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 210000002700 urine Anatomy 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- HJTAZXHBEBIQQX-UHFFFAOYSA-N 1,5-bis(chloromethyl)naphthalene Chemical compound C1=CC=C2C(CCl)=CC=CC2=C1CCl HJTAZXHBEBIQQX-UHFFFAOYSA-N 0.000 description 5
- 239000000706 filtrate Substances 0.000 description 5
- 238000013100 final test Methods 0.000 description 5
- 238000010998 test method Methods 0.000 description 5
- 239000000654 additive Substances 0.000 description 4
- 230000000996 additive effect Effects 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 210000002381 plasma Anatomy 0.000 description 4
- 210000002966 serum Anatomy 0.000 description 4
- 238000003556 assay Methods 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 235000019420 glucose oxidase Nutrition 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- CDBAKLRDFBGJOX-UHFFFAOYSA-K sodium arsenate Chemical compound [Na+].[Na+].[Na+].[O-][As]([O-])([O-])=O CDBAKLRDFBGJOX-UHFFFAOYSA-K 0.000 description 3
- PTLRDCMBXHILCL-UHFFFAOYSA-M sodium arsenite Chemical compound [Na+].[O-][As]=O PTLRDCMBXHILCL-UHFFFAOYSA-M 0.000 description 3
- MNSRNEWGVNQDQV-UHFFFAOYSA-M sodium metaarsenate Chemical compound [Na+].[O-][As](=O)=O MNSRNEWGVNQDQV-UHFFFAOYSA-M 0.000 description 3
- SZZLSXCPHWCVHE-UHFFFAOYSA-K trisodium;trioxido(sulfanylidene)-$l^{5}-arsane Chemical compound [Na+].[Na+].[Na+].[O-][As]([O-])([O-])=S SZZLSXCPHWCVHE-UHFFFAOYSA-K 0.000 description 3
- MHUWZNTUIIFHAS-XPWSMXQVSA-N 9-octadecenoic acid 1-[(phosphonoxy)methyl]-1,2-ethanediyl ester Chemical compound CCCCCCCC\C=C\CCCCCCCC(=O)OCC(COP(O)(O)=O)OC(=O)CCCCCCC\C=C\CCCCCCCC MHUWZNTUIIFHAS-XPWSMXQVSA-N 0.000 description 2
- DJHGAFSJWGLOIV-UHFFFAOYSA-L Arsenate2- Chemical compound O[As]([O-])([O-])=O DJHGAFSJWGLOIV-UHFFFAOYSA-L 0.000 description 2
- 108010015776 Glucose oxidase Proteins 0.000 description 2
- 239000004366 Glucose oxidase Substances 0.000 description 2
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 229910052785 arsenic Inorganic materials 0.000 description 2
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 2
- WQZGKKKJIJFFOK-VFUOTHLCSA-N beta-D-glucose Chemical compound OC[C@H]1O[C@@H](O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-VFUOTHLCSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000003086 colorant Substances 0.000 description 2
- 206010012601 diabetes mellitus Diseases 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229940116332 glucose oxidase Drugs 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 230000003617 peroxidasic effect Effects 0.000 description 2
- 239000011541 reaction mixture Substances 0.000 description 2
- 229940047047 sodium arsenate Drugs 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- GZCGUPFRVQAUEE-UHFFFAOYSA-N 2,3,4,5,6-pentahydroxyhexanal Chemical compound OCC(O)C(O)C(O)C(O)C=O GZCGUPFRVQAUEE-UHFFFAOYSA-N 0.000 description 1
- DJHGAFSJWGLOIV-UHFFFAOYSA-N Arsenic acid Chemical class O[As](O)(O)=O DJHGAFSJWGLOIV-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- WQZGKKKJIJFFOK-QTVWNMPRSA-N D-mannopyranose Chemical compound OC[C@H]1OC(O)[C@@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-QTVWNMPRSA-N 0.000 description 1
- 108090000790 Enzymes Proteins 0.000 description 1
- 102000004190 Enzymes Human genes 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- PQLVXDKIJBQVDF-UHFFFAOYSA-N acetic acid;hydrate Chemical compound O.CC(O)=O PQLVXDKIJBQVDF-UHFFFAOYSA-N 0.000 description 1
- 230000021736 acetylation Effects 0.000 description 1
- 238000006640 acetylation reaction Methods 0.000 description 1
- 150000001312 aldohexoses Chemical class 0.000 description 1
- WQZGKKKJIJFFOK-PHYPRBDBSA-N alpha-D-galactose Chemical compound OC[C@H]1O[C@H](O)[C@H](O)[C@@H](O)[C@H]1O WQZGKKKJIJFFOK-PHYPRBDBSA-N 0.000 description 1
- 229940000489 arsenate Drugs 0.000 description 1
- 230000003190 augmentative effect Effects 0.000 description 1
- 235000013405 beer Nutrition 0.000 description 1
- 210000001124 body fluid Anatomy 0.000 description 1
- 239000010839 body fluid Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000994 depressogenic effect Effects 0.000 description 1
- 235000005911 diet Nutrition 0.000 description 1
- 230000037213 diet Effects 0.000 description 1
- 229940088598 enzyme Drugs 0.000 description 1
- 239000002532 enzyme inhibitor Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 229930182830 galactose Natural products 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229940093920 gynecological arsenic compound Drugs 0.000 description 1
- 229920001903 high density polyethylene Polymers 0.000 description 1
- 239000004700 high-density polyethylene Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- -1 polypropylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 238000005057 refrigeration Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 150000004992 toluidines Chemical class 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/66—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving blood sugars, e.g. galactose
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T436/00—Chemistry: analytical and immunological testing
- Y10T436/14—Heterocyclic carbon compound [i.e., O, S, N, Se, Te, as only ring hetero atom]
- Y10T436/142222—Hetero-O [e.g., ascorbic acid, etc.]
- Y10T436/143333—Saccharide [e.g., DNA, etc.]
- Y10T436/144444—Glucose
Definitions
- This invention relates to a new and improved diagnostic composition which is useful for the quantitative determination of glucose in fluids, particularly body fluids such as urine, plasma, blood and the like.
- glucose in blood and urine is of great importance for diabetic patients whose diets must be controlled so as to regulate sugar intake and who must frequently be guided in this regard by regular checks on blood and urine glucose.
- Diabetes screening programs are dependent on the availability of rapid, inexpensive and accurate methods of glucose determination.
- U.S. Pat. 3,008,- 879 describes a means for testing biological fluids for their glucose content which'involves a combination comprising an enzyme system having glucose oxidase activity, a material having peroxidative activity, a primary indicator material which is capable of being preferentially oxidized to a colored form in the presence of hydrogen peroxide and the material having peroxidative activity and, as a secondary indicator, a material which is capable of reducing the preferentially oxidized primary indicator material While simultaneously becoming colored.
- the Folin- Wu and Nelson-Somogyi test methods can be applied only to protein-free filtrates of blood serum or plasma. There is some loss of specificity and reliability because of saccharoids and other reducing compounds that cannot be completely removed in preparation of a protein-free filtrate with resulting values higher than true glucose levels. Other disadvantages include the limited stability of the test reagents, the instability of the final test color,
- the glucose-oxidase test is a highly specific test for glucose when correctly done with pure materials. A protein-free filtrate is required. Other disadvantages include the sensitivity and limited stability of the test reagents, the necessary purity and standardization of the glucoseoxidase enzyme, the errors arising from interfering enzyme inhibitors, and the extreme care necessary during the three minute heating process where a matter of seconds can critically affect the accuracy of results.
- the o-toluidine test is a simple, rapid, reliable and economical method for glucose determination. Importantly, there is no need for protein-free filtrates although the test can be performed with such filtrates.
- the test can be performed directly with blood serum or plasma.
- Orthotoluidine is the only reagent required. Acetic acid solutions are stable for at least six months.. This stability is enhanced by the addition of thiourea. The final test color has good stability.
- An important disadvantage, however, of o-toluidine is its susceptibility to oxidation with its resultant effect on test sensitivity. The depressed sensitivity of the reagent results in a regression line with a lower slope when the optical densities of the final test colors are plotted against sugar concentrations, with serious loss of assay accuracy.
- the object of this invention is to prow'de an improved diagnostic composition containing o-toluidine and an arsenic compound for the simple, rapid, inexpensive and accurate quantitative determination of glucose in the biological fluids of humans.
- This invention is concerned with a diagnostic composition containing o-toluidine for the quantitative determination of glucose in such biological fluids as blood and urine. It has been found that the incorporation of an arsenic compound in the o-toluidine reagent solution increases the sensitivity of the test reagent and increases the stability of the final test color in the assay procedure.
- the o-toluidine test method for the quantitative determination of glucose in blood and urine involves the formation of a colored complex of glucose and o-toluidine in glacial acid which follows Beers law. The green color, read at 630 nm., is stable 97%) after standing one hour in air at 25 C.
- o-Toluidine is relatively sensitive to oxidation. Bulk supplies of uniform quality and purity are difiicult to obtain, with Eastman Chemical Company the preferred source. Freshly distilled o-toluidine is, of course, eminently suitable.
- the reagent composition contains from about 2 to about 10% of ortho-toluidine.
- Thiourea is preferably added as a color stabilizer at a concentration of from about 0.1 to about 1%, preferably 0.2%.
- the stabilizing effect is augmented by storage of the composition under nitrogen at a temperature range of about 25 C. to preferably refrigerator temperature (4-5 C.
- the intensity of the color formed by o-toluidine with glucose is a function of o-toluidine concentration.
- o-Toluidine in glacial acid is slowly acetylated under room temperature storage, with the o-toluidine concentration dropping approximately 50% in about 8 months. This acetylation is inhibited by adding water to the formulation in the amount of about 2 to about 20%, preferably 6%.
- the addition of 6% water to the glacial acetic acid solution of o-toluidine lowers the freezing point to about 2 C., and thus allows the preferable storage of the homogenous 3 reagent composition at refrigerator temperature (45 C.).
- arsenate salt or oxide of arsenic increases the sensitivity of the o-toluidine reagent to glucose up to 120% as reflected in the slope of the optical density curve of the final test colors.
- Sodium arsenate is the preferred arsenic compound and is added to the reagent composition at the preferred concentration of about 0.05%.
- Other suitable arsenic compounds at the same concentration may be selected from the group consisting of the following:
- sodium orthoarsenate Na AsO -12H O sodium mono-H-orthoarsenate: Na HAsO '12H O sodium di-H-orthoarsenate: NaH AsO -H O sodium metaarsenate: NaAsO sodium arsenite: NaAsO arsenic trioxide: As O arsenolite: AS406 claudetite: AS406 arsenic pentoxide: As O sodium thioarsenate: Na AsS -8H O
- the color formed by the o-toluidine, with and without arsenate additive, is quite stable for the first hour.
- the thiourea placed in an Erlenmeyer flask is dissolved in fresh glacial acetic acid.
- Freshly opened o-toluidine (Eastman Chemical Company) is added dropwise to the stirred acetic acid solution.
- Sodium mono-H-orthoarsenate Na HASO -7H O
- the reagent composition, under nitrogen with prior nitrogen deaeration, is packaged in dark glass bottles or bottles made from high density polyethylene or polypropylene.
- the packaged material is preferably stored under refrigeration (45 C.).
- Test procedure EXAMPLE II The preparation of the o-toluidine test reagent of Example I is repeated in turn with sodium orthoarsenate sodium mono-H-orthoarsenate (Na HAsO -12H O), sodium di-H-orthoarsenate (NaH AsO -H O), sodium metaarsenate (NaAsO sodium arsenite (NaAs0 arsenic trioxide (AS203), arsenolite (As O claudetite (AS406, arsenic pentoxide (As O and sodium thioarsenate (Na AsS -8H O) in place of sodium mono-H-orthoarsenate (Na HAsO -7H O), with comparable test results.
- sodium orthoarsenate sodium mono-H-orthoarsenate Na HAsO -12H O
- sodium di-H-orthoarsenate NaH AsO -H O
- EXAMPLE III An o-toluidine reagent composition is prepared by the method of Example I by mixing together the following ingredients in the following proportions by weight:
- a diagnostic composition for quantitatively determining glucose in the biological fluids of humans which comprises and aqueous acetic acid solution of otoluidine, thiourea and an arsenic compound selected from the group consisting of sodium orthoarsenate (Na AsO -12H O), sodium mono H-orthoarsenate (Na HAsO -7H O), sodium mono-H-orthoarsenate (Na HAsO -12H O), sodium di H orthoarsenate (NaH AsO -H O), sodium metaarsenate (NaAsO sodium arsenite (Na-AsO arsenic trioxide (AS203), arsenolite (AS406), claudetite (AS406), arsenic pentoxide (As O and sodium thioarsenate (Na AsS -8H O).
- an arsenic compound selected from the group consisting of sodium orthoarsenate (Na AsO -12H
- arsenic compound is sodium mono-H-orthoarsenate (Na HAsO 3.
- said composition comprises by weight about 4% toluidine, 0.2% thiourea, 0.05% sodium mono-H-orthoarsenate.
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Hematology (AREA)
- Molecular Biology (AREA)
- Urology & Nephrology (AREA)
- Biomedical Technology (AREA)
- Chemical & Material Sciences (AREA)
- Immunology (AREA)
- Food Science & Technology (AREA)
- Analytical Chemistry (AREA)
- Microbiology (AREA)
- Cell Biology (AREA)
- Biotechnology (AREA)
- Medicinal Chemistry (AREA)
- Physics & Mathematics (AREA)
- Diabetes (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Pathology (AREA)
- Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)
- Investigating Or Analysing Biological Materials (AREA)
Abstract
AN O-TOLUIDINE REAGENT COMPOSITION CONTAINING AN ARSENIC COMPOUND FOR USE IN THE DETERMINATION OF GLUCOSE IN BIOLOGICAL FLUIDS.
Description
United States Patent 3,778,384 DIAGNOSTIC COMPOSITION FOR THE QUANTI- TATIVE DETERMINATION OF GLUCOSE Joseph Francis Dooley, Waterford, Conn., assignor to Pfizer Inc., New York, N.Y.
No Drawing. Continuation-impart of application Ser. No. 203,840, Dec. 1, 1971. This application July 28, 1972, Ser. No. 275,926
Int. Cl. G01n 21/06, 33/16 U.S. Cl. 252-408 3 Claims ABSTRACT OF THE DISCLOSURE An o-toluidine reagent composition containing an arsenic compound for use in the determination of glucose in biological fluids.
CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of co-pending application Ser. No. 203,840 filed Dec. 1, 1971.
BACKGROUND OF THE INVENTION This invention relates to a new and improved diagnostic composition which is useful for the quantitative determination of glucose in fluids, particularly body fluids such as urine, plasma, blood and the like.
The detection and quantitative determination of glucose in blood and urine is of great importance for diabetic patients whose diets must be controlled so as to regulate sugar intake and who must frequently be guided in this regard by regular checks on blood and urine glucose. Diabetes screening programs are dependent on the availability of rapid, inexpensive and accurate methods of glucose determination.
Procedures for the detection of sugar in blood and urine are well known in clinical chemistry. The Folin-Wu and Nelson-Somogyi procedures utilize copper reduction for the detection and determination of sugar. U.S. Pat. 3,008,- 879 describes a means for testing biological fluids for their glucose content which'involves a combination comprising an enzyme system having glucose oxidase activity, a material having peroxidative activity, a primary indicator material which is capable of being preferentially oxidized to a colored form in the presence of hydrogen peroxide and the material having peroxidative activity and, as a secondary indicator, a material which is capable of reducing the preferentially oxidized primary indicator material While simultaneously becoming colored.
The use of o-toluidine solutions in glacial acetic acid for the determination of aldosaccharides in serum or plasma is described by Hultman, E., Nature, 183, 108 (1959) and Dubowski, K. M., Clin. Chem., 8, 215 (1962). Ordinarily, glucose is the only aldohexose present in clinically significant amounts in blood serum; other aldohexoses that may be present in minute quantities are mannose and galactose. This test method is based on the formation of a colored complex of glucose and o-toluidine in glacial acetic acid. The concentration of this complex, and thus the intensity of the green color developed, is directly proportional to the concentration of glucose present in the reaction mixture, and can be measured photometrically.
For the determination of glucose in blood, the Folin- Wu and Nelson-Somogyi test methods can be applied only to protein-free filtrates of blood serum or plasma. There is some loss of specificity and reliability because of saccharoids and other reducing compounds that cannot be completely removed in preparation of a protein-free filtrate with resulting values higher than true glucose levels. Other disadvantages include the limited stability of the test reagents, the instability of the final test color,
ice
and critical factors in the test procedure involving temperature, heating time and alkalinity of reaction mixture.
The glucose-oxidase test is a highly specific test for glucose when correctly done with pure materials. A protein-free filtrate is required. Other disadvantages include the sensitivity and limited stability of the test reagents, the necessary purity and standardization of the glucoseoxidase enzyme, the errors arising from interfering enzyme inhibitors, and the extreme care necessary during the three minute heating process where a matter of seconds can critically affect the accuracy of results.
The o-toluidine test is a simple, rapid, reliable and economical method for glucose determination. Importantly, there is no need for protein-free filtrates although the test can be performed with such filtrates. The test can be performed directly with blood serum or plasma. Orthotoluidine is the only reagent required. Acetic acid solutions are stable for at least six months.. This stability is enhanced by the addition of thiourea. The final test color has good stability. An important disadvantage, however, of o-toluidine is its susceptibility to oxidation with its resultant effect on test sensitivity. The depressed sensitivity of the reagent results in a regression line with a lower slope when the optical densities of the final test colors are plotted against sugar concentrations, with serious loss of assay accuracy.
The object of this invention is to prow'de an improved diagnostic composition containing o-toluidine and an arsenic compound for the simple, rapid, inexpensive and accurate quantitative determination of glucose in the biological fluids of humans.
SUMMARY OF THE INVENTION This invention is concerned with a diagnostic composition containing o-toluidine for the quantitative determination of glucose in such biological fluids as blood and urine. It has been found that the incorporation of an arsenic compound in the o-toluidine reagent solution increases the sensitivity of the test reagent and increases the stability of the final test color in the assay procedure.
DETAILED DESCRIPTION OF THE INVENTION The o-toluidine test method for the quantitative determination of glucose in blood and urine involves the formation of a colored complex of glucose and o-toluidine in glacial acid which follows Beers law. The green color, read at 630 nm., is stable 97%) after standing one hour in air at 25 C.
o-Toluidine is relatively sensitive to oxidation. Bulk supplies of uniform quality and purity are difiicult to obtain, with Eastman Chemical Company the preferred source. Freshly distilled o-toluidine is, of course, eminently suitable. The reagent composition contains from about 2 to about 10% of ortho-toluidine. Thiourea is preferably added as a color stabilizer at a concentration of from about 0.1 to about 1%, preferably 0.2%. The stabilizing effect is augmented by storage of the composition under nitrogen at a temperature range of about 25 C. to preferably refrigerator temperature (4-5 C.
The intensity of the color formed by o-toluidine with glucose is a function of o-toluidine concentration. o-Toluidine in glacial acid is slowly acetylated under room temperature storage, with the o-toluidine concentration dropping approximately 50% in about 8 months. This acetylation is inhibited by adding water to the formulation in the amount of about 2 to about 20%, preferably 6%. The addition of 6% water to the glacial acetic acid solution of o-toluidine lowers the freezing point to about 2 C., and thus allows the preferable storage of the homogenous 3 reagent composition at refrigerator temperature (45 C.).
The addition of an arsenate salt or oxide of arsenic increases the sensitivity of the o-toluidine reagent to glucose up to 120% as reflected in the slope of the optical density curve of the final test colors. An increase in sensitivity, over solutions containing no arsenic additive, is observed with the addition of 0.01% arsenic compound. The sensitivity increase levels off in the region of about 0.5% arsenic compound additive. Sodium arsenate is the preferred arsenic compound and is added to the reagent composition at the preferred concentration of about 0.05%. Other suitable arsenic compounds at the same concentration may be selected from the group consisting of the following:
sodium orthoarsenate: Na AsO -12H O sodium mono-H-orthoarsenate: Na HAsO '12H O sodium di-H-orthoarsenate: NaH AsO -H O sodium metaarsenate: NaAsO sodium arsenite: NaAsO arsenic trioxide: As O arsenolite: AS406 claudetite: AS406 arsenic pentoxide: As O sodium thioarsenate: Na AsS -8H O The color formed by the o-toluidine, with and without arsenate additive, is quite stable for the first hour. However, an increase in stability is noted for the sodium arsenate additive solution after hours with a 32% decrease in color retained, compared to a 38% decrease for the control solution. This increased color stability is important when large numbers of test samples are run, and assay readings cannot be immediately made.
The following examples are provided to illustrate the present invention, but not to limit its scope.
EXAMPLE I Preparation of reagent An o-toluidine reagent composition is prepared by mixing together the following ingredients in the following proportions by weight:
Percent o-Toluidine 4 Thiourea 0.2 Glacial acetic acid 90 Water 6 Na HASO 7H O 0.05
The thiourea placed in an Erlenmeyer flask is dissolved in fresh glacial acetic acid. Freshly opened o-toluidine (Eastman Chemical Company) is added dropwise to the stirred acetic acid solution. Sodium mono-H-orthoarsenate (Na HASO -7H O) dissolved in water is added with gentle stirring under nitrogen. The reagent composition, under nitrogen with prior nitrogen deaeration, is packaged in dark glass bottles or bottles made from high density polyethylene or polypropylene. The packaged material is preferably stored under refrigeration (45 C.).
Test procedure EXAMPLE II The preparation of the o-toluidine test reagent of Example I is repeated in turn with sodium orthoarsenate sodium mono-H-orthoarsenate (Na HAsO -12H O), sodium di-H-orthoarsenate (NaH AsO -H O), sodium metaarsenate (NaAsO sodium arsenite (NaAs0 arsenic trioxide (AS203), arsenolite (As O claudetite (AS406, arsenic pentoxide (As O and sodium thioarsenate (Na AsS -8H O) in place of sodium mono-H-orthoarsenate (Na HAsO -7H O), with comparable test results.
EXAMPLE III An o-toluidine reagent composition is prepared by the method of Example I by mixing together the following ingredients in the following proportions by weight:
Percent o-Tol-uidine 2-10 Thiourea 0.10-1.0 Na HAsO -7H O 0.010.5 Water 2.0-20 Glacial acetic acid 96-685 What is claimed is:
1. A diagnostic composition for quantitatively determining glucose in the biological fluids of humans which comprises and aqueous acetic acid solution of otoluidine, thiourea and an arsenic compound selected from the group consisting of sodium orthoarsenate (Na AsO -12H O), sodium mono H-orthoarsenate (Na HAsO -7H O), sodium mono-H-orthoarsenate (Na HAsO -12H O), sodium di H orthoarsenate (NaH AsO -H O), sodium metaarsenate (NaAsO sodium arsenite (Na-AsO arsenic trioxide (AS203), arsenolite (AS406), claudetite (AS406), arsenic pentoxide (As O and sodium thioarsenate (Na AsS -8H O).
2. The diagnostic composition of claim 1 wherein said arsenic compound is sodium mono-H-orthoarsenate (Na HAsO 3. The diagnostic composition of claim 1 wherein said composition comprises by weight about 4% toluidine, 0.2% thiourea, 0.05% sodium mono-H-orthoarsenate.
(Na HAsO 7H O),
6% water and glacial acetic acid.
References Cited UNITED STATES PATENTS 3,001,915 9/1961 Fonner 23-253 TP 3,453,180 7/1969 Fraser 23-253 TP 3,607,077 9/1971 Hartel 23-230 B 3,615,228 10/1971 Thiegs 23-230 B 3,653,836 4/1972 Gruher 23-230 B 3,653,841 4/1972 Klein 23-230 B 3,660,559 5/1972 Buckert 23-230 B MORRIS O. WOLK, Primary Examiner S. MARANTZ, Assistant Examiner US. Cl. X.R. 2323O B
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US20384071A | 1971-12-01 | 1971-12-01 | |
| US27592672A | 1972-07-28 | 1972-07-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3778384A true US3778384A (en) | 1973-12-11 |
Family
ID=26898948
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US00203840A Expired - Lifetime US3792044A (en) | 1971-12-01 | 1971-12-01 | Method for determining glucose with o-toluidine reagent containing an arsenic compound |
| US00275926A Expired - Lifetime US3778384A (en) | 1971-12-01 | 1972-07-28 | Diagnostic composition for the quantitative determination of glucose |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US00203840A Expired - Lifetime US3792044A (en) | 1971-12-01 | 1971-12-01 | Method for determining glucose with o-toluidine reagent containing an arsenic compound |
Country Status (1)
| Country | Link |
|---|---|
| US (2) | US3792044A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3947377A (en) * | 1972-02-08 | 1976-03-30 | Boehringer Mannheim Gmbh | Stabilized indicator compositions containing 9-γ-aminopropyl)-3-aminocarbazole |
| US4330299A (en) * | 1981-03-09 | 1982-05-18 | Evreka, Inc. | Article and method for measuring glucose level in body fluids |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4058366A (en) * | 1976-02-06 | 1977-11-15 | Continental Oil Company | Determination of flow characteristics of petroliferous formations |
| US4814247A (en) * | 1983-01-26 | 1989-03-21 | University Of Medicine And Dentistry Of New Jersey | Method for determining the existance and/or the monitoring of a pathological condition in a mammal |
| US4705756A (en) * | 1983-01-26 | 1987-11-10 | University Of Medicine And Dentistry Of New Jersey | Method of determining the existence and/or the monitoring of a pathological condition in a mammal |
-
1971
- 1971-12-01 US US00203840A patent/US3792044A/en not_active Expired - Lifetime
-
1972
- 1972-07-28 US US00275926A patent/US3778384A/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3947377A (en) * | 1972-02-08 | 1976-03-30 | Boehringer Mannheim Gmbh | Stabilized indicator compositions containing 9-γ-aminopropyl)-3-aminocarbazole |
| US4330299A (en) * | 1981-03-09 | 1982-05-18 | Evreka, Inc. | Article and method for measuring glucose level in body fluids |
Also Published As
| Publication number | Publication date |
|---|---|
| US3792044A (en) | 1974-02-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3979262A (en) | Compositions and methods for the determination of oxidizing agents | |
| US3298789A (en) | Test article for the detection of glucose | |
| US3814668A (en) | Method and device for the semi-quantitative determination of glucose in aqueous fluids | |
| US3598704A (en) | Diagnostic device for various sugars | |
| US5516700A (en) | Automated urinalysis method | |
| HK82686A (en) | Process and diagnostic agents for detecting redox reactions | |
| US5156947A (en) | Process for reduction of the matrix effect in a fructosamine determination assay | |
| US3558435A (en) | Diagnostic agents for use in the determination of hydroperoxides and of peroxidate-active substances and methods for manufacturing and using the same | |
| US4673654A (en) | Composition for determining peroxidase-like activity of hemoglobin | |
| Morin et al. | Single Glucose Oxidase—Peroxidase reagent for two-minute determination of serum glucose | |
| US3630847A (en) | Diagnostic agent for use in the determination of hydroperoxides and of peroxidate-active substances | |
| EP0575515A1 (en) | Improved method and reagent for determination of an analyte | |
| US4143080A (en) | Method and reagent for the assay of hydroperoxide | |
| US3087794A (en) | Chemical test for differentiating leucocytes from erythrocytes | |
| JPH0425000B2 (en) | ||
| US3663175A (en) | Method of determining hemoglobin in blood | |
| US4803158A (en) | Composition used for the determination of beta-hydroxybutyric acid and a method for preparing the said composition | |
| US5055388A (en) | Process and reagent composition for determination of fructosamine in body fluids | |
| US5935805A (en) | Measurement of bilirubin albumin binding | |
| Meites et al. | Studies on the use of the van den Bergh reagent for determination of serum bilirubin | |
| US3778384A (en) | Diagnostic composition for the quantitative determination of glucose | |
| SU416969A3 (en) | ||
| Reljic et al. | New chromogen for assay of glucose in serum | |
| Asp | Improved method for the assay of phenylglycosidase activity with a 4-aminoantipyrine reagent | |
| EP0586397B1 (en) | Improved method and reagent for determination of an analyte |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AS | Assignment |
Owner name: WARNER-LAMBERT COMPANY, 201 TABOR RD., MORRIS PLAI Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:PFIZER INC.;REEL/FRAME:003853/0905 Effective date: 19810409 |