US 2449274 A
Description (OCR text may contain errors)
Patented Sept. 14, 1948 PATENT Nnllizrawing. 1-: Application May? 27 1946,
15""1'0 Claims. 3.1 1' 1 This invention :relates htoiself -indicat1ngl .bacteriocidal agents and to methods of preparing suchragfents.
. iHeretoforeitfhas been-proposedto test the bacteriocidal strengthof varioussolutions :and .com-.
more rapidly than othersconcerned.
results in conjunction with quaternary ammonium c'ompcunds as selfeindicatingihacteriooldal'.
compositions which in aqueous solutions-undergo a sharp and distinct change in; color and. fluorescence characteristics upon reductionalnvpotencyto certain predetermined values. p itions-by withdrawing asample; radding cer- *When these dyes: are .addedzto.thequaternary tainwdyes and reagentsandobservingthe (color ammonium-compo runder"60flsidfimtion, effects with respect to a standardwSuch p-roceesulting color and fiuorescence are tire y-"difduresrare exemplifieflqby the disclosures of U. s. ferent'from theseich aracteristics:of ithe dye itself, patentstor-Lehmkuhl;;1;986;403, ,dated, January but when the bacteriocidal potency 'offth'e c'om- 1; 11935;: "an'dvScharer. 2,385,471, dated. September P s t eC ed t'fl fi i p 25 .19%; aItwhas also-.been prgpgsed mu s value belowwhich it is.'undesirablectoirely 'upon patent tmE mnd; 1534 02 21,. d t d. May .11; .192 it, "the rather sudden changeliin 500101. and .fiuot add. fluorescent dyes" of t mm t p rescence will directly-indicate the :-:existence of ein type to inorganic cleaningtcompositionswto such condition. This sudden changeiislinrsharp progressivelynindicate: their; relative strengths in tto I gradual -.changes of... thevtypes vknown in the prior. vart for .use in such. colorometric jazlngthezxwashing'andsrinsing of tableware;;es e comparisons as pI-I determinations. By virtuepf cia'llyuin public.placesmsuchoas.c-restaurantssand the present invention, a mere .glance at. the .bath Soda, fountaing stgt dgFf deral.,requirem ents will suffice to indicate whether or not it is satishavewbeen.promulgatedin an=efifortto-limit bacfi l further teriafl'counts: of.thetfarticles;zprocessedmo such Laboratory and operatingtestvsihavebeen 6011- low values as to preventtransmission:,ofdisease. ducted withvarious dyesiandquatemary"ammo" Even. though. thelpmprietorsiof .suchpublic places nium compounds-and with-various contaminants. mayr be coopera tjve in their -lefiorts. to onform and thus "far the tests have verified the results with--suchregulations, :theyv-have never heretoherein proposed- 7 fore' been-providedwith af-simpleumeansfor de- Among the materialsiwithwhich highly Satis" termining whenltheebacteriocidal poteneyof their factory results have been obtained; in that the rinseisolutionswhasrbecomeaspentiorJreducedto an fluorescence of thedye is quenched The iageand frequency ofsr en e dition tothe'bacteriocide, and-restored when a ingrr'the solutions i'cann'ot berrelied upon- .to assure predetermined degree contamination the :requirednbacterlocidal-ristrengtirxof -such=com- Produced) aqueous m tagethel with DOSilZlDIlSWSilTCBZ BIBQSEd time-iandwextentof-use c0101" changes aspreviouslw'referred amine are 11015117116, solericriteriair 'somercontaminants rrefollowing: duceifthe effectivenessr'of..these solutions much aflLauryl, py-pidjnium 1 1 1g%1 .1 gaL Uranine /y gm. Quaternaryammoniuma' compounds':have' now H 755 been; accepted '1 rathenfgenerally: 'bywarious --Fed- 1121 01 coefficient 28+ eral rand l'o'ca'l agenciestasinhibitors "of bacterial b; :Lauryl .pyridinium chloride 1 12% 1. gal. growth. and: transmissionyxaand it iswith respect 4 muorescein to the: use of such: quaternary ammonium icompH 7 55 pounds that the presentzsinventionvis-"primarily p m tflza+ c. Npyridinium chloride (10 -1 gal. It: has been' foundrinsaccordancez withrthi'swin- Uranine gm. Vention, that when' variousdyes of characteristic i pH 4.91 color and fluorescence are admixed with certain dw N-pyridi-nium'chloride..(.10%.)n W. 1 gal. types of quaternary ammonium -compounds pos- L---- /z.gmsessing particularphenol coefficients, the charac- WPH teristics of color andfiuorescienceare sharply d de .(.1 modified. Then when the phenol coefficient of Fluorescem the compositionjhas becomie reduced 't'o a predetermined value by contamination, a marked and ggg g imum'hmnude' ratherabrupt change in olor and fluorescence 78 occurs,thus providing a userjor inspector with W anuninistakable visual indication/of that,"condi- 1 i jkjjjllijgfi' H d-.78 Fluorescent dyes of the phthalein classthave 21 mm. dim y m 42 1.;ga,1 now been found to produce highly satisfactory -..Uranine mm..-" a
i. Cetyl pyridinium chloride (c /2%)"; lgal. Fluorescein 1A.; gm. pH 6.00
The pH values of these aqueous baths are noted as being variously in the acid and alkaline ranges, a condition which would thus far appear to be not of a critical nature. Certain of these compositions have been subjected to the effects of various atmospheric temperatures, natural light, ultra violet light and reducing agents without adversely affecting their performance for the purposes intended.
After diluting these compositions to the minimum strengths at which their use conforms with F. D. A. standards (F. D. A. Circular 198), they were contaminated with. a 35% soap solution (which if added in sufficient quantity would inactivate them as bacteriocides) and at the first indication of the restored fluorescence and color, they were found to retain a substantial proportion of their original bacteriocidal activity, thus providing a definite safety factor.
An example of a practical application of invention is as follows:
Used drinking glasses were cleansed with warm water and washing compound, rinsed, in clear water, and then immersed in a bath containing one ounce of the following composition to four gallons of Water:
12% lauryl pyridinium chloride having a phenol coefiicient of 28+ (F. D. A. Circular 198) 88% water gm. fluorescein per gal.
The glasses were then placed in a rack to drain.
So long as the aqueous composition retained its original light straw color it was found to possess satisfactory baoteriocidal properties. This color, accompanied by no apparent fluorescence under any conditions observed, remained substantially unchanged throughout many washing and rinsing operations. Then, suddenly, when the contamination reached a critical predetermined point, the bath'assumed a definite green color accompanied by a marked fluorescence. A determination of the phenol coefficient at this point showed that the value had dropped to a point substantially below its original strength, and at which renewal would be desired, yet it retained definite bacteriocidal activity sufiicient .to constitute a safety factor.
The quaternary ammonium compounds successfully employed to produce these desired results have included quaternary ammonium salts, wherein the ammonium nitrogen is incorporated in an aromatic ring or resonating system, which compounds can be characterized a cationic or invert soaps, detergents, wetting agents, disinfectants, germicides or bacteriocides.
The effect of the apparent loss or reduction of fluorescence of the dyes upon admixture with the quaternary ammonium compounds may be referred to as quenching. Whether or not fluorescence could be detected under special lighting or photographi-cally is of no practical importance where the impression upon the human eye is involved, and for the effects here under consideration, the expression "apparent fluorescence may be employed to advantage.
Many and valuable applications of this invention will suggest themselves to those skilled in the art, among which are uses in swimming pools, foot baths, dish washing, and various other places where contamination should be readily detectable.
The examples outlined herein will adequately serve to illustrate the invention without restricting it beyond the scope of the appended claims.
1. A bacteriocidal composition comprising a baoteriocidal quaternary ammonium compound and a fluorescent indicating agent quenched therein and responsive at a predetermined reduced bacteriocidal strength to change the visual aspect of the composition, said indicating agent being selected from the group consisting of fluorescein and uranine.
2. A bacteriocidal composition comprising a bacteriocidal alkyl pyridinium halide and a fluorescent phthalein dye selected from the group consisting of fluorescein and uranine quenched therein.
3. A bacteriocidal composition comprising a bacteriocidal alkyl pyridinium halide and a fluorescein indicator quenched therein.
4. A bacteriocidal composition comprising laury1 pyridinium chloride and a fluorescein indicator quenched therein.
5. A bacteriocidal composition comprising an aqueous vehicle, a quaternary ammonium bacteriocide and a fluorescent indicator selected from the group consisting of fluorescein and uranine quenched therein responsive at a predetermined bacterio-cidal strength to change the visual aspect of the-composition.
6. A bacteriocldal composition comprising an aqueous vehicle, a quaternary ammonium bacterlocide having a relatively high initial phenol coefiicien-t and a fluorescent indicator selected from the group consisting of fluorescein and uranine quenched therein responsive at a predetermined reduced phenol coefli-cient to change the visual aspect of the composition.
'7. A method for rendering reduced potency of a quaternary ammonium bacteriocide composition self indicating comprising incorporating therein a fluorescence agent selected from the group con-' sisting of fluorescein and uranin which changes the visual aspect of the composition at apredetermined bacteriocidal strength.
8. A method for rendering reduced strength of an alkyl pyridinium halide bacteriocidal composition self indicating comprising incorporating therein a fluorescein indicator which changes the visual aspect of the composition at a predeter mined bacteriocidal strength.
9. A method for rendering reduced strength of an alkyl pyridinium halide bacteriocidal composition self indicating comprising incorporating therein a uranine indicator which changes'the visual aspect of the composition at a predetermined bacteriocidal strength.
10. A bacteriocidal composition comprisinga bacteriocidal alkyl pyridinium halide and a uranine indicator quenched therein.
HARRY R. BR-OLL.
REFERENCES CITED Thefollowing references are of record in the file of this patent:
UNITED STATES PATENTS 7 Date Scharer "A"; Sept. 25, 19%5