natgillin/translations-raw huggingface dataset:
Katalase har et pH optimum på omkring 7, hvilket svarer til fysiologisk pH i de fleste celler.
The pH optimum for catalase is around 7, which corresponds to the physiological pH in most cells.
Afvigelser i pH vil medføre ændringer i enzymets konfiguration, hvilket mindsker enzymets aktivitet.
Deviations in pH may lead to changes in the configuration of the enzyme, reducing the activity of the enzyme.
Figur 7: Katalasens effektivitet ved pH 4, 6, 7 og 10.
Figure 7: The efficiency of the catalase at pH 4, 6, 7 and 10.
Katalasens pH afhængighed blev undersøgt i en serie forsøg, hvor pH i bufferen i reaktionskammeret varierede fra 4-10 (Figur 7).
The pH dependency of the catalase was examined in a series of tests using buffer solutions of varying pH (4-10, Fig. 7) in the reaction chamber.
Alle forsøgene blev udført i triplikat, og pH i kammeret målt både før og efter reaktionen.
All of the tests were conducted in triplicate, and the pH in the chamber was measured both before and after the reaction.
Variation i bufferens pH indenfor intervallet 4-10 påvirker reaktions-hastigheden, men ikke det målte iltniveau ved reaktionens afslutning (Figur 7).
Using a buffer at pH values varying from 4-10 affected the reaction kinetics, however not the oxygen level measured at the end of the reaction (Fig. 7).
Reaktionen forløber hurtigst ved pH 6, hvor al peroxid er omdannet til ilt indenfor ½ minut.
The reaction was fastest at pH 6, where all of the peroxide was converted to oxygen within half a minute.
3.3 Afprøvning af katalase bioassayet på peroxider i ren form
3.3 Testing of the catalase bioassay on peroxides in pure form
Katalase bioassayet blev testet på forskellige peroxider med henblik på at få bekræftet et sammenfald mellem det målte og det forventede peroxidindhold i de anvendte opløsninger.
The catalase bioassay was tested on different peroxides in order to confirm a relationship between the peroxide content expected and that measured in the solutions used.
Derudover blev metodens reproducerbarhed testet i en serie uafhængige forsøg som grundlag for en beskrivelse af metodens præcision ved anvendelse på de respektive peroxider.
Furthermore, the reproducibility of the method was tested in a series of independent experiments to describe its accuracy when used on the respective peroxides.
3.3.1 Brint- og ureaperoxid
3.3.1 Hydrogen and urea peroxide
Katalase bioassayet er blevet anvendt på en række forskellige koncentrationer af brint- og ureaperoxid i ren form, hvor resultatet enten er sammenlignet med det forventede i henhold til produktspecifikationen (ureaperoxid) eller med mængden fundet ved KMnO4- titrering.
The catalase bioassay was applied to a number of different concentrations of hydrogen and urea peroxide in pure form, where the results were either compared to the expected quantity according to the product specifications (urea peroxide), or to the quantity found from KMnO4 titration (hydrogen peroxide).
Det sidste var nødvendigt med brintperoxid på grund af stoffets ustabilitet ved opbevaring og dermed usikre angivelse af indholdet fra producentens side.
The latter was required with the hydrogen peroxide because the substance is unstable when stored and therefore the manufacturer's statement of content is uncertain.
Aflæsningerne af elektrodesignalet er ved alle målingerne foretaget efter 300 sekunder (5 minutter) efter tilsætning af katalase.
In all the measurements, the probe signal was read 300 seconds (5 minutes) after adding the catalase.
Figur 8: Sammenhæng imellem den potentielle ilt-frigivelse beregnet på baggrund af en KMnO4 titrering (åbne symboler) og bestemt ved tilsætning af en varieret mængde H2O2 til katalase bioassayet (sorte symboler).
Figure 8: Relationship between the potential oxygen release calculated on the basis of a KMnO4titration (unshaded symbols) and determined by adding a varying quantity of H2O2 to the catalase bioassay (shaded symbols).
På begge akser vises procent af bufferens iltmætning efter reaktionens afslutning.
Both axes show the percentage of oxygen saturation in the buffer at the reaction's completion.
Der er en fuldstændig lineær sammenhæng mellem den forventede iltudvikling beregnet på baggrund af en redoxtitrering og iltudviklingen bestemt ved katalase bioassayet for hele måleområdet (Figur 8).
For hydrogen peroxide, a linear relationship between the expected oxygen development calculated on the basis of a redox titration, and the oxygen development determined using the catalase bioassay was observed (Fig. 8).
Katalase bioassayet er dermed anvendeligt til brintperoxid-bestemmelse inden for hele det måleinterval som afgrænses af bufferens iltmætning.
Thus, the catalase bioassay can be applied to hydrogen peroxide determination within the entire measurement interval, which is defined by the oxygen saturation of the buffer.
Ifølge produktoplysningerne var koncentrationen af den indkøbte brintperoxid angivet til 30 %.
According to the product specifications, the concentration of the hydrogen peroxide purchased was stated to be 30%.
KMnO4-titrering bestemte koncentrationen til 34,4 % med en standardafvigelse på 0,2 (n=4) mens katalase bioassayet bestemte koncentrationen til 33,6 med en standardafvigelse på 0,7 (n=14).
The KMnO4titration determined the concentration to be 34.4% with a standard deviation of 0.2 (n=4), whereas the catalase bioassay determined the concentration to be 33.6% with a standard deviation of 0.7 (n=14).
Figur 9: Sammenhæng imellem den teoretisk mulige ilt-frigivelse beregnet ud fra producentens oplysninger om stoffets renhed (åbne symboler) og bestemt ved tilsætning af en varieret mængde ureaperoxid til katalase bioassayet (sorte symboler).
Figure 9: Relationship between the theoretically possible oxygen release calculated on the basis of the manufacturer's information about the purity of the substance (unshaded symbols) and determined by adding a varying quantity of urea peroxide to the catalase bioassay (shaded symbols).
På begge akser vises procent af bufferens iltmætning efter endt reaktion.
Both axes show the percentage of oxygen saturation in the buffer at the reaction's completion.
For ureaperoxid ses ligeledes en fuldstændig overensstemmelse mellem den målte og den teoretisk mulige iltudvikling beregnet ud fra tilsat mængde stof (Figur 9).
Similar to hydrogen peroxide, urea peroxide showed a linear correlation between the measured and the theoretically possible oxygen development calculated on the basis of the quantity of substance added (Fig. 9).
På den baggrund konkluderes, at al den bundne peroxid frigives fra den tilsatte ureaperoxid og spaltes af katalase-enzymet indenfor den pågældende måleperiode.
Therefore, it can be concluded that the bound peroxide is released from the urea peroxide and that it is cleaved by the catalase enzyme within the measurement period in question.
Producenten opgiver koncentrationen af ureaperoxid til 97 % mens katalase bioassayet bestemte koncentrationen til 97,4 % med en standardafvigelse på 0,9 (n=12).
The manufacturer stated the concentration of urea peroxide to be 97%, whereas the catalase bioassay determined it to be 97.4% with a standard deviation of 0.9 (n=12).
På baggrund af KMnO4 og S2O3-titrering blev ureaperoxid indholdet bestemt til henholdsvis 95,83 % med en standardafvigelse på 0,4 (n=3) og 99,17 % med en standardafvigelse på 0,3 (n=3), hvilket afviger noget fra producentens angivelser og bestemmelsen ved hjælp af katalase bioassayet.
On the basis of KMnO4 and S2O3 titrations, the content of urea peroxide was determined to be 95.83% with a standard deviation of 0.4 (n=3) and 99.17% with a standard deviation of 0.3 (n=3), respectively, which deviates somewhat from the manufacturer's specifications and the result determined by the catalase bioassay.
Calciumperoxid har ved fysiologisk pH (pH=7) en meget lav opløselighed i vand (<0,01 % v. 20 °C), og calciumperoxid indgår i forskellige reaktioner med vand afhængigt af pH.
At physiological pH (pH=7), calcium peroxide has a very low solubility in water (<0.01% at 20°C), and calcium peroxide reacts differently with water at different pH values.
Opløseligheden af calciumperoxid stiger med faldende pH og under dannelse af frit brintperoxid.
The solubility of calcium peroxide increases as the pH value drops, and during the production of free hydrogen peroxide.
Mængden af dannet brintperoxid afhænger helt af pH.
The quantity of hydrogen peroxide being produced depends entirely on the pH value.
Med henblik på at fastlægge den optimale pH for analyse af produkter indeholdende calciumperoxid, blev der udført en serie forsøg hvor pH i blev varieret fra 4-10.
In order to determine the optimal pH value when analysing products containing calcium peroxide, a series of tests in which the pH value was set at various values from 4-10 were carried out.
Calciumperoxid har ifølge producenten (Sigma, MA USA) en renhed på 75 %.
According to the manufacturer (Sigma, MA, USA), the calcium peroxide has a purity of 75%.
Dermed vil 1 mg calciumperoxid maksimalt kunne frigøre 0,16647 mg O2.
Thus 1 mg calcium peroxide will be able to release a maximum of 0.16647 mg O2.
Genfindingsprocenten er herefter beregnet ud fra formlen:
The recovery percentage was then calculated using the following formula:
(mg O2 produceret/ 0,16647 mg) x 100 = genfinding (%)
mg O2 produced/ 0.16647 mg) x 100 = recovery (%)
Iltudviklingen er fundet ved aflæsning af den producerede mængde ilt efter 10 minutter, da signalet endnu ikke var stabiliseret efter 5 minutter.
The release of oxygen was found by conducting a reading of the oxygen produced after 10 minutes, as the signal was still not stable after 5 minutes.
Alle forsøg er udført i 3-6 gentagelser og pH i reaktionskammeret er målt både før og efter forsøget.
All tests were conducted in repetitions of 3-6, and the pH in the reaction chamber was measured both before and after the test.
Figur 10: Sammenhæng mellem ilt-produktionen (procent af maximalt mulige) fra calciumperoxid som funktion af pH.
Figure 10: Relationship between oxygen production (as a percentage of the maximum possible) from calcium peroxide and pH.
Ved høj pH er iltudviklingen fra calciumperoxid lavere end ved de optimale pH-værdier omkring 6-7 (Figur 10).
At a high pH value, the production of oxygen from calcium peroxide was lower than at around 6-7 (Fig. 10).
Calciumperoxid kræver lav pH (surt miljø) for at kunne bringes på en opløst form.
Calcium peroxide requires a low pH value (an acidic environment) to dissolve in water.
Figur 11: Sammenhæng mellem reaktionshastighed og pH i calciumperoxid stamopløsningen.
Figure 11: Correspondence between reaction rate and pH in the calcium peroxide stock solution.
Det ses af Figur 11, at reaktionshastigheden er størst når calciumperoxid tilsættes efter at være opløst i en H2SO4 -opløsning ved pH 2.
Fig. 11 shows that the reaction rate was highest when calcium peroxide was added after it had been dissolved in an H2SO4 solution of pH 2.
Injiceres i stedet en opslemning af calciumperoxid i vand med pH 11,2, foregår reaktionen noget langsommere, men ender på fuldstændig samme niveau efter 10 minutter.
If calcium peroxide in water at pH 11.2 was injected instead, the reaction rate was slower, but it ended at the same level after 10 minutes.
Denne forskel skyldes dels, at calciumperoxid ved den lave pH allerede har frigivet den samlede brintperoxid-pulje, og dels at tilsætningen af calciumperoxid i uopløst form sænker hastigheden for frigivelsen af brintperoxid til væskefasen.
This difference is due partly to the fact that the calcium peroxide at low pH had already released the total pool of peroxide, and partly because the addition of calcium peroxide in undissolved form slowed down the speed at with which hydrogen peroxide was released to the liquid phase.
3.3.3 Natriumperborater og natriumpercarbonat
3.3.3 Sodium perborates and sodium percarbonate
Traditionelt har natriumperborate-monohydrat, NaBO3·H2O (CAS nr. 10332-33-9) og natriumperborate-tetrahydrat, NaBO3·4H2O (CAS nr. 10486-00-7) været brugt som blegemidler i vaskemidler.
Traditionally, sodium perborate monohydrate, NaBO3H2O (CAS no. 10332-33-9) and sodium perborate tetrahydrate, NaBO34H2O (CAS no. 10486-00-7) have been used as bleaching agents in washing powder.
Indenfor de seneste år, er natriumperborat også taget i brug i tandblegemidler.
In recent years, sodium perborate has also been used in tooth-whitening agents.
Modsat produkterne indeholdende brintperoxid og ureaperoxid findes natriumperborater herhjemme kun i produkter der benyttes af tandlæger.
In contrast to products containing hydrogen peroxide and urea peroxide, in Denmark sodium perborates are only found in products used by dentists.
Brintperoxid releaseren natriumpercarbonat findes endnu ikke i tandblegeprodukter som anvendes i Danmark (1, 8).
The hydrogen peroxide releaser, sodium percarbonate, is not yet found in tooth-whitening products in use in Denmark (1, 8).
Peroxid-dannelsen og iltudviklingen fra de to natriumperborater og natriumpercarbonat blev testet.
Peroxide release and oxygen development from the two sodium perborates and sodium percarbonate were tested.
De to perborater adskiller sig ved at have en forskellig mængde krystalvand bundet.
The two perborates differ from one another by having a differing amount of crystal water bound in them.
Natriumperborat-monohydrat kan teoretisk frigive brintperoxid svarende til 34 % af molekylevægten, mens natriumperborat-tetrahydrat afgiver brintperoxid svarende til 22 % af molekylevægten.
Theoretically, sodium perborate monohydrate can release hydrogen peroxide corresponding to 34% of its molecular weight, whereas sodium perborate tetrahydrate releases hydrogen peroxide corresponding to 22% of its molecular weight.
Natriumpercarbonat kan potentielt frigive en brintperoxid andel svarende til 28 % af stoffets molekylvægt.
Sodium percarbonate can potentially release hydrogen peroxide corresponding to 28% of its molecular weight.
Disse andele indgår i beregningen af genfindingsprocenten efter iltdannelsen i katalase bioassayet.
These percentages are included in the calculation of the recovery percentage after the formation of oxygen in the catalase bioassay.
Der blev for alle tre stoffer lavet en forsøgsserie med fire gentagelser. pH var justeret til 7, og der blev injiceret 100 - 250 µl af en 1 % opløsning af de tre stoffer.
For all three substances, a series of tests were made with four repetitions. pH was adjusted to 7 and 100-250 µl of a 1% solution of the three substances were injected.
Signalet var i alle tilfælde stabiliseret inden for ca. 2 minutter, resultaterne blev aflæst efter 5 minutter og iltmængden anvendt til beregning af genfindingsprocenterne (se Tabel 3).
The signal stabilised in all cases within about 2 minutes, the results were read after 5 minutes, and the oxygen quantity was used to calculate the recovery percentages (see table 3).
Tabel 3: Genfinding - natriumperborater og natriumpercarbonat.
Table 3: Recovery - sodium perborates and sodium percarbonate.
Valideringen viste, at der for alle de testede stoffer var en meget fin overensstemmelse mellem den teoretiske og den målte iltudvikling.
The validation showed that for all substances tested there was very good correspondence between the theoretical and the measured oxygen development.
Genfindingsprocenterne afviger i alle tilfælde mindre end 1,9 %, hvilket dermed beskriver metodens usikkerhedsmargin under de valgte analysebetingelser.
The recovery percentages deviated in all cases by less than 1.9%, and this describes the method's level of uncertainty under the analytical conditions chosen.
På baggrund af metodeudviklingen og afprøvning på en række af de rene stoffer som anvendes i tandblegemidler, er en protokol til analyse af peroxid-indholdet i tandblegemidler opstillet:
On the basis of the method development and the tests on the pure substances used in tooth-whitening products, a protocol for analysis of the peroxide content in tooth-whitening products was set up.
Med udgangspunkt i, at der anvendes et lukket analysekammer på ca. 100 ml i henhold til beskrivelse i afsnit 3.1, opstilles hermed følgende standardbetingelser:
Based on the fact that the analysis uses a sealed analysis chamber of about 100 ml in accordance with the description in section 3.1, the following standard conditions can be established:
Analysen udføres ved 22 °C.
The analysis is conducted at 22°C.
Yderligere oplysninger om produkterne, såsom forhandler, varenummer, batchnummer mv. kendes af Miljøstyrelsen.
The Danish Environmental Protection Agency has been provided with further information about the products, (such as retailer, product no., batch no. etc.).
Parallelt med katalase-metoden, er alle produkter tillige analyseret på traditionel vis ved hjælp af redox-titreringer.
In parallel with the catalase method, all the products were also analysed traditionally using redox titrations.
Alle produkter og de to rene stoffer, brintperoxid og ureaperoxid, er titreret med kaliumpermanganat, mens produkterne indeholdende ureaperoxid desuden er titreret med natriumthiosulfat.
All the products and the two pure substances, hydrogen peroxide and urea peroxide, were titrated with potassium permanganate, while the products containing urea peroxide were also titrated with sodium thiosulfate.
Resultaterne fra både titreringer og test af katalase-assayet ses i Tabel 6, sammen med producentens angivelse af indholdsstoffer.
The results of both titrations and test of the catalase bioassay are shown in Table 6, along with the manufacturers' specifications of contents.
For tre af produkterne har det ikke været muligt at få oplyst mængden af aktivstof.
For three of the products, information on the quantity of active substance in the product was not available.
Generelt ses en fin overensstemmelse mellem koncentrationer fundet ved titrering og ved katalase assayet.
In general, there was good correspondence between the concentrations found through titration and those found using the catalase bioassay.
Særlig lille er afvigelserne mellem tallene fra KMnO4-titreringer og katalase assayet.
The deviations were particularly small between the concentrations found through KMnO4 titrations and the catalase bioassay.
For at afgøre, om det var en fejl ved assayet eller produktet blev endnu et sæt købt og analyseret.
In order to determine whether this lack of peroxide content was due to a flaw in the assay or in the product, another set of products was purchased and analysed.
Denne gang blev der fundet peroxid i både ”E” og ”F” ved begge analysemetoder.
This time around, peroxide was found in product “E” as well as “F” by both methods.
Bestemmelse af peroxid koncentrationen i de testede tandblegemidler er ved hjælp af katalase bioassayet foretaget på flere forskellige prøvekoncentrationer og i mindst 14 gentagelser per produkt.
Determination of the peroxide concentration in the tooth-whitening products was conducted on several different sample concentrations using the catalase bioassay, and in at least 14 repetitions per product.
Tilsvarende er assayet afprøvet på de rene stoffer brintperoxid og ureaperoxid i en række forskellige koncentration.
Correspondingly, the assay was tested on the pure substances, hydrogen peroxide and urea peroxide, in a number of different concentrations.
Variationskoefficienten på målinger af produkter med katalase bioassayet er 0,9 - 3 %.
The coefficient of variation for measurements of products using the catalase bioassay was 0.9 - 3%.
Tilsvarende er variationen på målinger af de rene aktivstoffer 0,9 - 1,9 %.
Correspondingly, the variation for measurements of the pure, active substances was 0.9 - 1.9%.
Redoxtitreringerne er foretaget i tre gentagelser på både produkter og rene stoffer.
The redox titrations were conducted in repetitions of three on both products and pure substances.
For kaliumpermanganat titreringerne af tandblegeprodukterne er variationskoefficienten 0,4-2,4 %.
For the potassium permanganate titrations of the tooth-whitening products, the coefficient of variation was 0.4 - 2.4%.
For de rene stoffer er variationen på målingerne 0,4 - 1 %.
For the pure substances, the variation of the measurements was 0.4 - 1%.
For natriumthiosulfat titreringerne ses en meget stor variation for produkterne: 9,4 - 23,8 %.
For the sodium thiosulfate titrations, the variation was very high for the products, namely 9.4 - 23.8%.
Dog er variationen på natriumthiosulfat titrering af ureaperoxid i ren form kun 0,33 %.
However, the variation for sodium thiosulfate titration of urea peroxide in pure form was only 0.33%.
I forhold til de testede produkter er variationen (præcisionen) på katalase bioassayet således sammenligneligt med variationen på den kemiske analyse baseret på en kaliumpermanganat titrering, hvorimod den fremstår mere præcis end natriumthiosulfat titreringerne.
With regard to the tested products, the variation of (accuracy of) the catalase bioassay was therefore comparable to the variation of the chemical analysis based on potassium permanganate titration, while the catalase bioassay appeared more accurate than the sodium thiosulfate titrations.
I forhold til producenternes angivelse af peroxid-indhold i produkterne afviger koncentrationsbestemmelserne foretaget med katalase bioassayet med 3,3 - 5,9 %.
With regard to the manufacturers' specifications of the peroxide content in the products, the determinations of concentration using the catalase bioassay deviated by 3.3 - 5.9%.
Koncentrationer fundet ved kaliumpermanganat-titrering afviger 3,4 - 7,7 % og natriumthiosulfat-titrering 4,6 - 28,9 % fra producentens oplysninger.
The concentrations found from potassium permanganate titration deviated from the manufacturers' specifications by 3.4 - 7.7% and those from sodium thiosulfate titration by 4.6 - 28.9%.
Igen er variationen på resultater fra katalase-assayet altså helt sammenligneligt med resultater fra kaliumpermanganat-titrering, og begge dele er meget bedre end natriumthiosulfat-titreringer.
Therefore, the variability of the catalase bioassay was comparable to the variability of the potassium permanganate titration, while the variability of the sodium thiosulfate titration was higher.
Her bekræftes, at der i de testede tandblegeprodukter ikke findes stoffer der hæmmer katalase-aktiviteten.
These confirm that the tooth-whitening products tested do not contain substances that inhibit the catalase activity.
Det udviklede katalase bioassay er altså fuldt ud brugbart til analyse af de pågældende produkter.
Hence, the catalase bioassay developed is suitable for the analysis of tooth-whitening products.
5 Resultatvurdering og konklusion
5 Assessment of results and conclusion
En ny metode og protokol til analyse af peroxid-indhold i tandblegeprodukter er udviklet.
A new method and protocol for the analysis of peroxide content in tooth-whitening products was developed.
Metoden bygger på måling af iltudvikling efter enzymatisk omdannelse af peroxid til ilt og vand.
The method is based on the measurement of changes in oxygen concentrations following enzymatic conversion of peroxide to oxygen and water.
Sammenlignet med traditionelle analysemetoder baseret på titreringer med permanganat og thiosulfat er det nyudviklede katalase bioassay nemt at udføre, og alle peroxidforbindelser - uanset om de er bundet til forskellige 'releasere' - kan måles på en gang.
Compared to traditional analytical methods, based on titrations with permanganate and thiosulfate, the newly developed catalase bioassay is easy to conduct, and all peroxide compounds - irrespective of whether they are bound to different releasers - may be measured at once.
De fundne peroxid-indhold i tandblegeprodukterne svarer godt overens med produkt-oplysningerne.
The peroxide contents found in the tooth-whitening products correspond well with the product specifications.
Resultaterne af metodeudviklingen og analysen af de undersøgte produkter kan kortfattet opsummeres således:
Results of method development and product analysis can be summarised as follows:
Bestemmelse af peroxid indhold i tandblegeprodukter ved hjælp af katalase bioassayet er nemt og hurtigt at udføre
Determination of peroxide content in tooth-whitening products through use of catalase bioassay is quick and easy.