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Study on test paper for rapid detection of concentration of o-phthalaldehyde disinfectant

Release time:

2022-05-16

Objective To prepare a rapid test paper for detecting whether the concentration of o-phthalaldehyde (OPA) disinfectant meets the application requirements. Methods A variety of factors affecting the color reaction of the test paper were studied by comparing the color of the test paper. Results Na2 SO3, glycine, The concentration of KH2 PO4 and methylene blue were 8, 80, 40 and 0. 04 g / L, respectively, and the detection time was 2 min. The addition of KH2 PO4 can greatly improve the color development rate. Dyeing the test paper into blue substrate is more conducive to color recognition. Conclusion The prepared test paper has a good detection effect on unilateral OPA products, and the stability and reproducibility of the test paper are good. The method is simple, fast and feasible.

o-phthalaldehyde( OPA) As a new type of medical efficientVenom 〔^{1 has many advantages}^,^{Such as strong sterilization ability}^,^{Use low concentration}^{and short action time, etc.}^〔²^,³^{>> 〕}.However,OPA Strong volatility can causeIts concentration decreases after repeated use,Sterilization effect becomes weak.Guaranteed to killBacteria effect,should be maintained OPA concentration in0． 3% Above,and carry it onRegular inspection.Traditional detection methods such as spectrophotometry 〔⁴^{] and}^{Chromatography, etc. [] 〔}⁵^{All have certain limitations 〔}⁶^{>> 〕},For example,need accordingly of instruments and operation skills, etc.,Not applicable to ordinary medical personnel in the useFast in the process.,Simple determination of concentration.

The test paper method is a chemical colorimetric method based on the different shades of color of the reaction products.,Compared with the color card can be semi quantitative detection,be ableMeet the requirements of medical rapid detection.

Materials and Methods

1． 1 Materials

EL204analytical balance;DF － 101S magnetic stirrer;XMTD

-8222 Vacuum drying oven;Medium speed qualitative filter paper;Sodium sulfite,GlycinolAcid,Potassium dihydrogen phosphate and methylene blue are analytically pure;o-phthalaldehyde( 98% ) ; o-phthalaldehyde disinfectant( 0． 5% ～ 0． 6% ) ,AboveMaterials are domestic commercially available products.

1． 2 Principle

Using glycine and OPA The product formed after the reaction is dark yellowShallow different(Aldehydes can react with amino acids or amines to form imines

-Schiff base^〔⁷>> 〕,It usually has a certain color.)to determine its concentration, reaction formula^〔⁸>> 〕Figure 1。In addition,OPA Can react with sulfiteproduces a colorless compound,As Na₂ SO₃ Reaction,The reaction formula is shown in Figure 2 shown in.The reaction is fast and irreversible.in the simultaneous presence of glycine and

Na₂ SO₃ in the mixed solution,OPA First Na₂ SO₃ Reaction,again

glycine reaction.The two are mixed into a solution in a certain proportion and the test is made. Paper,Usein detectionOPA Solution.When OPA When the concentration is low,

Na₂ SO₃ Overdose,OPA does not react with glycine,No color on the test paperChange; When OPA When the concentration is high,OPA Overdose,Its anti-glycineShould,The test strip shows the corresponding color.By the presence or absence of color or shade of colorCan be quickly judged OPA concentration.

This test adds an appropriate amount

KH₂ PO₄ ,Make the mother liquor a stable buffer system,greatly promoteGlycine and OPA color reaction.

1． 3 Method

1． 3． 1 Test paper pretreatment Take medium speed qualitative filter paper in absolute ethanolSoak in 2 h Post-drying,and then cut it 1 cm ×1 cm GaugeLattice,Spare.

1． 3． 2 colorimetric card systemPreparation Preparation motherLiquid,itsMedium,Na₂ SO₃ ,GanAmmoniaAcid,KH₂ PO₄ and methylene blue concentrations, respectivelyFor8,80,40 and

0． 04 g / L.Immerse the filter paper in the mother liquor10 minAfter removing,PlacingOn a horizontal glass plate 50℃Lower 1 h Drying,Spare.

The mass concentration was determined by test paper respectively. 0． 1% ,0． 2% ,

0． 3% ,0． 4% and 0． 5% of OPA Solution,Color rendering 2 min When,Use the camera to shoot the color of the test paper at this time and make a color comparison card..

This test is the color effect on the data contrast test paper.,IntroductionPantone Color Card.Select the most suitable series according to the color of the reaction productColor,The color number is 607U － 613U,Figure 3。By contrast color testThe color number corresponding to the paper,Select the best ratio of raw materials.

Results

2． 1 Test results of influencing factors

2． 1． 1 chromogenic agentthe shadowRang This test by glycine and overQuantityof OPA AntiShades shall be presentedDifferent yellow.Color,Further judgmentBroken OPAconcentration,Therefore, the amount of glycine has a certain effect on the detection.PointsDo not prepare glycine concentration 20,60,80,100 and 160 g / L the motherLiquid,Preparation of filter paper and testing,In2 minWhen comparing the Pantone color card and rememberRecording number,See Table for results 1.