natgillin/translations-raw huggingface dataset:
100, 250 and 300 ml beakers
Čaše 100, 250 in 300 ml
Glass chromatograph column, internal diameter 21-23 mm, length 400 mm, fitted with a sintered glass disc and a stopcock
Steklena kromatografska kolona z notranjim premerom 21–23 mm, dolžine 400 mm, opremljena s sintrano stekleno ploščico in petelinčkom
10, 50, 100 and 200 ml measuring cylinders
Merilni valji prostornine 10, 50, 100 in 200 ml
100 and 250 ml flasks
Bučke prostornine 100 in 250 ml
Rotary evaporator
Rotavapor
10 ml conical-bottomed centrifuge tubes with groundglass stopper
Epruvete za centrifugiranje prostornine 10 ml s koničnim dnom in obrušenim zamaškom
Centrifuge for 10 and 100 ml tubes
Centrifuga za epruvete prostornine 10 in 100 ml
Thermostat permitting a stable temperature of 40 ± 0,5 °C
Termostat, ki omogoča vzdrževanje temperature pri 40 °C ± 0,5 °C
1 and 2 ml graduated pipettes
Merilni pipeti prostornine 1 in 2 ml
1 ml hypodermic syringe
Brizgalka prostornine 1 ml
100 μl microsyringe
Mikrobrizgalka prostornine 100 μl
1000 ml funnel
Lij-ločnik, 1000 ml
Capillary gas chromatograph with an on-column cold injector for direct injection of the sample into the column and a furnace able to maintain the selected temperature to approximately 1 °C
Plinski kromatograf za kapilarne kolone, opremljen z injicirnim sistemom za hladno injiciranje vzorca neposredno v kolono in pečjo, ki lahko vzdržuje izbrano temperaturo znotraj 1 °C
On-column cold injector for direct injection of the sample into the column
Injektor za hladno injiciranje vzorca neposredno v kolono
Flame ionisation detector and electrometer
Plamensko ionizacijski detektor in elektrometer
Recorder-integrator adapted to the electrometer with a response rate no greater than 1 sec and a variable paper roll rate
Rekorder-integrator, kompatibilen z elektrometrom, z odzivnim časom, manjšim od 1 sekunde, in nastavljivo hitrostjo pomika papirja
Capillary column made of glass or fused silica 8-12 metres long, 0,25-0,32 mm internal diameter, covered with methylpolysiloxane or phenyl methylpolysiloxane 5 %, 0,10-0,30 μm thick, useable at 370 °C
Steklena ali kvarčna kapilarna kolona dolžine 8 do 12 m, z notranjim premerom 0,25 do 0,32 mm, pokrita z metilpolisiloksanom ali 5-odstotnim fenil metilpolisiloksanom, debeline 0,10–0,30 μm, ki jo je mogoče uporabiti pri 370 °C
10 μl microsyringe fitted with a hardened needle, at least 7,5 cm long for direct on-column injection.
Mikrobrizgalka prostornine 10 μl z nesnemljivo, vsaj 7,5 cm dolgo iglo, za neposredno vbrizganje na začetek kolone
Silica gel with a grain size of between 0,063 and 0,200 mm (70/280 mesh) prepared as follows: Place the silica gel in a porcelain capsule, dry in an incubator at 160 °C for four hours, then leave to cool at room temperature in a desiccator.
Silikagel z velikostjo delcev med 0,063 in 0,200 mm (70/280 mesh), pripravljen na naslednji način: silikagel damo v porcelansko posodico, ga pri 160 °C 4 ure sušimo v sušilniku, nato pa pustimo, da se na sobni temperaturi ohladi v eksikatorju.
Add water equivalent to 5 % of the mass of the silica gel as follows: Weigh 152 g silica gel into an Erlenmeyer flask then add 8 g of distilled water, stopper and shake gently to distribute the water evenly.
Nato dodamo količino vode, ki ustreza 5 % teže silikagela: v erlenmajerico prostornine 500 ml natehtamo 152 g silikagela in dodamo 8 g destilirane vode, zamašimo ter homogeniziramo.
Leave to stand for at least 12 hours before use.
Pred uporabo pustimo mirovati vsaj 12 ur.
n-hexane (for chromatography)
n-heksan (kromatografske čistoče)
Isopropanol, 1/1 (v/v) aqueous solution
Izpropanol, vodna raztopina 1/1 (V/V)
Pancreatic lipase.
Pankreatična lipaza.
It must have an activity of between 2,0 and 10 lipase units per mg. (Pancreatic lipases with an activity of between 2 and 10 units per mg enzyme are commercially available.)
Aktivnost uporabljene lipaze mora biti med 2,0 in 10 lipaznimi enotami na mg (V prodaji so pankreatične lipaze z aktivnostjo med 2 in 10 enotami na mg encima.)
Buffer solution of trishydroxymethylaminomethane: 1 M aqueous solution adjusted to pH 8 (potentiometric control) by conc. HCl (1/1 v/v)
Pufrska raztopina tris-hidroksi-metilaminometana: 1 M vodna raztopina, ki ji s koncentrirano HCI (1/1 V/V) uravnamo pH na vrednost 8 (preverimo s pH-metrom)
Enzyme-quality sodium cholate, 0,1 % aqueous solution (this solution must be used within two weeks of its preparation)
Natrijev holat, encimske čistosti, 0,1-odstotna vodna raztopina (to raztopino je treba uporabiti v petnajstih dneh po pripravi)
Calcium chloride, 22 % aqueous solution
Kalcijev klorid, 22-odstotna vodna raztopina
Diethyl ether for chromatography
Dietil eter kromatografske čistoče
Developer solvent: mixture of n-hexane/diethyl ether (87:13 v:v)
Elucijsko topilo: mešanica n-heksana/dietilnega etra (87/13) (V/V)
Sodium hydroxide, 12 % by weight solution
Natrijev hidroksid, 12-odstotna raztopina v masnih odstotkih
Phenolphthalein, 1 % solution in ethanol
Fenolftalein, 1-odstotna raztopina v etanolu
Carrier gas: hydrogen or helium, for gas chromatography
Nosilni plin: vodik ali helij, za plinsko kromatografijo
Auxiliary gases: hydrogen, 99 % minimum purity, free from moisture and organic substances, and air, for gas chromatography, of the same purity
Pomožna plina: vodik, najmanj 99-odstoten, brez vlage in organskih snovi, in zrak, za plinsko kromatografijo in enake čistoče
Silanisation reagent: mixture of pyridine/hexamethyldisilazane, trimethylchlorosilane 9/3/1 (v/v/v). (Ready-to-use solutions are commercially available.
Regent za silaniziranje: mešanica piridina, heksametildisilazana, trimetilklorosilana v razmerju 9:3:1 (V/V/V) (V prodaji so raztopine, pripravljene za uporabo.
Other silylation reagents may be used, particularly bis-trimethylsilyl trifluoracetamide + 1 % trimethylchlorosilane, diluted with an identical volume of anhydrous pyridine.)
Uporabimo lahko tudi druge reagente za silaniziranje, zlasti bis-trimetilsilil trifluoroacetamid + 1-odstoten trimetilklorosilan, razredčen z enako količino brezvodnega piridina.)
Reference samples: pure monoglycerides or monoglyceride mixtures with a known percentage composition similar to that of the sample.
Referenčni vzorci: čisti monogliceridi ali mešanice monogliceridov, za katere je znano, da imajo podobno odstotkovno sestavo kot vzorec.
METHOD
POSTOPEK
Oils with a free acidity of less than 3 % do not need to be neutralised before chromatography on a silica gel column.
Olj z deležem prostih kislin, manjšim od 3 %, pred kolonsko kromatografijo ni treba nevtralizirati s silikagelom.
Oils with a free acidity of more than 3 % must be neutralised as per point 5.1.1.1.
Olja, katerih delež prostih kislin je večji od 3 %, je treba nevtralizirati v skladu s točko 5.1.1.1.
Pour 50 g of oil and 200 ml n-hexane into the 1000 ml funnel (3.13).
V lij-ločnik prostornine 1000 ml (3.13) vlijemo 50 g olja in 200 ml n-heksana.
Add 100 ml of isopropanol and a quantity of 12 % sodium hydroxide solution (4.11) equivalent to the free acidity of the oil plus 5 %.
Dodamo 100 ml izopropanola in tako količino 12-odstotne raztopine natrijevega hidroksida (4.11), da ustreza deležu prostih kislin, povečanemu za 5 odstotkov.
Shake vigorously for one minute.
Eno minuto močno stresamo.
Add 100 ml of distilled water, shake again and leave to stand.
Dodamo 100 ml destilirane vode, ponovno pretresemo in pustimo, da se usede.
After decanting, remove the lower layer containing the soaps.
Po ločevanju odstranimo spodnjo plast, ki vsebuje mila.
Remove any intermediate layers (mucilage and insoluble substances).
Odstranimo morebitne vmesne plasti (sluz in netopne snovi).
Wash the hexane solution of the neutralised oil with successive portions of 50-60 ml of the 1/1 (v/v) isopropanol/water solution (4.4) until the pink colouration of the phenolphthalein disappears.
Heksansko raztopino nevtraliziranega olja izpiramo z zaporednimi 50- do 60-mililitrskimi odmerki raztopine izopropanola in vode 1/1 (V/V) (4.4) tako dolgo, da je izpiralna faza nevtralna na fenolftalein.
Remove most of the hexane by vacuum distillation (use a rotary evaporator, for example) and transfer the oil into a 100 ml flask (3.5).
Večino heksana odstranimo z destilacijo v vakuumu (uporabimo na primer rotavapor) in olje prelijemo v 100-mililitrsko bučko (3.5).
Dry the oil in vacuum until the solvent is completely removed.
Olje sušimo v vakuumu, dokler se topilo v celoti ne odstrani.
After that procedure is completed, the acidity of the oil should be less than 0,5 %.
Po koncu tega postopka mora biti vsebnost kislin v olju manjša od 0,5 %.
Put 1,0 g of the oil prepared as above into a 25 ml Erlenmeyer flask (3.1) and dissolve in 10 ml of developer mixture (4.10).
V erlenmajerico prostornine 25 ml damo 1,0 g olja, pripravljenega po spodnjih navodilih (3.1), in ga raztopimo v 10 ml razvijalne mešanice (4.10).
Leave the solution to stand for at least 15 minutes before silica gel column chromatography.
Pred kolonsko kromatografijo s silikagelom raztopino pustimo mirovati najmanj 15 minut.
If the solution is cloudy centrifuge it to ensure optimum conditions for chromatography.
Če je raztopina motna, jo centrifugiramo, da zagotovimo optimalne pogoje za kromatografijo.
(Ready-to-use 500 mg silica gel SPE cartridges can be used).
(Uporabimo lahko komercialne 500-mg silikagelne kartuše SPE.)
Preparation of the chromatography column
Priprava kromatografske kolone
Pour about 30 ml of the developer solvent (4.10) into the column (3.3), insert a piece of cotton into the bottom part of the column using a glass rod; press to eliminate the air.
V kolono (3.3) vlijemo približno 30 m razvijalnega topila (4.10), s stekleno paličko v spodnji del kolone vstavimo košček vate; stisnemo, da odstranimo zrak.
In a beaker prepare a suspension of 25 g of silica gel (4.1) in about 80 ml of developer solvent and pour it into the column using a funnel.
V čaši pripravimo raztopino 25 g silikagela (4.1) v približno 80 ml razvijalne raztopine in jo z lijakom prelijemo v kolono.
Check that all the silica gel is in the column; wash with developer solvent (4.10), open the stopcock and allow the liquid to reach a level about 2 mm above the level of the silica gel.
Preverimo, da smo v kolono dali ves silikagel; speremo z elucijskim topilom (4.10), odpremo petelinček in pustimo, da raven tekočine seže približno 2 mm nad zgornjo raven silikagela.
Column chromatography
Kolonska kromatografija
Weigh accurately 1,0 g of sample prepared as in point 5.1 into a 25 ml Erlenmeyer flask (3.1).
V erlenmajerico prostornine 25 ml (3.1.) natehtamo natanko 1,0 g vzorca, ki smo ga pripravili v skladu s točko 5.1.
Dissolve the sample in 10 ml of developer solvent (4.10).
Vzorec raztopimo v 10 ml elucijskega topila (4.10).
Pour the solution into the chromatography column prepared as in point 5.1.3.
Raztopino prelijemo v kromatografsko kolono, ki smo jo pripravili v skladu s točko 5.1.3.
Avoid disturbing the surface of the column.
Pazimo, da ne premešamo površine kolone.
Open the stopcock and pour the sample solution until it reaches the level of the silica gel.
Odpremo ventil in pustimo raztopino vzorca odtekati, dokler ne doseže ravni silikagela.
Develop with 150 ml of the developer solvent.
Eluiramo s 150 ml razvijalnega topila.
Adjust the flow rate to 2 ml/min (so that 150 ml enters the column in about 60-70 minutes).
Količino pretoka nastavimo na 2 ml/min (tako da 150 ml odteče v kolono v približno 60–70 minutah).
Recover the eluate in a previously weighed 250 ml flask.
Eluat zberemo v 250-mililitrsko bučko z znano maso.
Evaporate the solvent under vacuum and remove the final traces of the solvent under a nitrogen current.
V vakuumu odparimo topilo in njegove zadnje sledi odstranimo s tokom dušika.
Weigh the flask and calculate the recovered extract.
Bučko stehtamo in izračunamo pridobljeni ekstrakt
(If ready-to-use silica gel SPE cartridges are used use the following method: Put 1 ml of solution (5.1.2) into the prepared cartridges with 3 ml of n-hexane.
(Če uporabljamo silikagelne kartuše SPE, storimo naslednje: v kartuše, ki smo jih predhodno kondicionirali s 3 ml n-heksana, vlijemo 1 ml raztopine (5.1.2).
After percolating the solution develop with 4 ml of n-hexane/diethyl ether 9/1 (v/v).
Po filtraciji raztopine razvijemo s 4 ml n-heksana/dietilnega etra 9/1 (V/V).
Recover the eluate in a 10 ml tube and evaporate to dry in a nitrogen current.
Eluat zberemo v 10-mililitrsko epruveto in ga z uvajanjem toka dušika odparimo do suhega.
Expose the dry residue to pancreatic lipase (5.2).
Na suhem preostanku pustimo učinkovati pankreatično lipazo (5.2).
(It is essential to check the fatty acid composition before and after crossing the SPE cartridge.)
Ključno je, da pred in po uporabi kartuše SPE preverimo sestavo maščobnih kislin.
Hydrolysis by pancreatic lipase
Hidroliza s pankreatično lipazo
Weigh into the centrifuge tube 0.1 g of the oil prepared as in point 5.1.
V epruveto centrifuge natehtamo 0,1 g olja, pripravljenega v skladu s točko 5.1.
Add 2 ml of buffer solution (4.6), 0,5 ml of the sodium cholate solution (4.7) and 0,2 ml of the calcium chloride solution, stirring well after each addition.
Dodamo 2 ml pufrske raztopine (4.6), 0,5 ml raztopine natrijevega holata (4.7) in 0,2 ml raztopine kalcijevega klorida, pri čemer po vsakem dodajanju dobro pretresemo.
Close the tube with the groundglass stopper and place in the thermostat at 40 + 0,5 °C.
Epruveto zapremo z obrušenim zamaškom in jo namestimo v termostat, naravnan na 40 ± 0,5 °C.
Add 20 mg of lipase, shake carefully (avoid wetting the stopper) and place the tube in the thermostat for exactly two minutes. Then remove it, shake vigorously for exactly 1 minute and leave to cool.
Dodamo 20 mg lipaze, previdno pretresemo (pazimo, da ne zmočimo zamaška) in damo epruveto za natanko 2 minuti v termostat, nato jo damo ven, jo natanko 1 minuto močno stresamo in pustimo, da se ohladi.
Add 1 ml of diethyl ether, stopper and shake vigorously, then centrifuge and transfer the ether solution into a clean, dry tube using a microsyringe.
Dodamo 1 ml dietilnega etra, zamašimo in močno stresamo, nato centrifugiramo ter raztopino etra z mikrobrizgalko prenesemo v čisto in suho epruveto.
Preparation of the silanised derivatives and gas chromatography
Priprava silaniziranih derivatov in plinska kromatografija
With a microsyringe insert 100 μl of solution (5.2.3) into a 10 ml conical-bottomed tube.
Z mikrobrizgalko prenesemo 100 μl raztopine (5.2.3) v epruveto prostornine 10 ml s koničastim dnom.
Remove the solvent under a slight nitrogen current, add 200 μl of silanisation reagent (4.15), stopper the tube and leave to stand for 20 minutes.
Topilo odstranimo z uvajanjem rahlega toka dušika, dodamo 200 μl reagenta za silaniziranje (4.15), zamašimo epruveto in pustimo mirovati 20 minut.
After 20 minutes, add 1 to 5 ml of n-hexane (depending on the chromatography conditions): the resulting solution is ready for gas chromatography.
Po 20 minutah dodamo 1 do 5 ml n-heksana (odvisno od kromatografskih pogojev): raztopina, ki jo dobimo, je nared za plinsko kromatografijo.
Operating conditions:
Pogoji za postopek so naslednji:
Injector temperature (on-column injector) lower than solvent boiling point (68 °C);
temperatura injektorja (injektor za vbrizgavanje v kolono) mora biti nižja od temperature vrelišča topila (68 °C),
Detector temperature: 350 °C;
temperatura detektorja: 350 °C,
Column temperature: programming of furnace temperature: 60 °C for 1 minute, increasing by 15 °C per minute up to 180 °C, then by 5 °C per minute up to 340 °C, then 340 °C for 13 minutes;
temperatura kolone: programiranje temperature peči: 1 minuto pri 60 °C, s hitrostjo segrevanja 15 °C na minuto, dokler ne dosežemo temperature 180 °C, nato s hitrostjo 5 °C na minuto, dokler ne dosežemo temperature 340 °C, nato 13 minut pri 340 °C,
Carrier gas: hydrogen or helium, set at a linear velocity sufficient to obtain the resolution reflected in Figure 1.
nosilni plin: vodik ali helij, nastavljen na ustrezno linearno hitrost, da dosežemo resolucijo, navedeno na Sliki 1.
The retention time of the C54 triglyceride must be 40 ± 5 minutes (see Figure 2). (The operating conditions indicated above are indicative.
Retencijski čas triglicerida C54 mora biti 40 + 5 minut (glej Sliko 2); (Pogoji za spodaj navedene postopke so okvirni.
Operators will have to optimise them to obtain the desired resolution.
Vsak izvajalec jih mora optimizirati, da doseže želeno resolucijo.
The peak corresponding to 2-glyceryl monopalmitate must have a minimum height equal to 10 % of the recorder scale.)
Najmanjša višina vrha za 2-gliceril monopalmitat mora biti enaka 10 % polne skale rekorderja.),
Quantity of substance injected: 0,5-1 μl of the n-hexane solution (5 ml) (5.3.3).
količina injicirane snovi: 0,5-1 μl raztopine (5 ml) n-heksana (5.3.3).
Identification of the peaks
Identifikacija vrhov
The individual monoglycerides are identified from their retention times and by comparison with those obtained for standard monoglyceride mixtures under the same conditions.
Posamezne monoacilglicerole identificiramo na podlagi dobljenih retencijskih časov in glede na čase, dobljene za standardne mešanice monogliceridov, analizirane pri enakih pogojih.
Quantitative evaluation
Kvantitativna analiza
The area of each peak is calculated using an electronic integrator.
Površina vsakega vrha se izračuna z elektronskim integratorjem.
The percentage of glyceryl monopalmitate is calculated from the ratio between the area of the corresponding peak and the areas of the peaks of all the monoglycerides (see Figure 2) using the formula:
Odstotek gliceril monopalmitata izračunamo iz razmerja med ustrezno površino vrha in vsoto površin vrhov vseh monoacilglicerolov (glej Sliko 2), in sicer na podlagi formule:
glyceryl monopalmitate (%): Ax
gliceril monopalmitat (%): Ax
area of the peak corresponding to glyceryl monopalmitate
površina vrha gliceril monopalmitata
ΣA sum of the areas of all the monoglyceride peaks
ΣA vsota površin vseh vrhov monoacilglicerolov
The result must be to one decimal place.
Rezultat je treba podati na eno decimalko natančno.
ANALYSIS REPORT
POROČILO O ANALIZI
The analysis report must specify:
V poročilu o analizi je treba podrobno navesti:
reference to this method,
sklicevanje na to metodo,
all the information needed for a full identification of the sample,
vse informacije, potrebne za popolno identifikacijo vzorca,
the analysis result,
rezultat analize,
any deviation from the method, whether as the result of a decision by the parties concerned or for another reason,
vsako odstopanje od te metode, ne glede na to, ali gre za odločitev zadevnih oseb ali zaradi kakega drugega razloga,
details to identify the laboratory, the date of the analysis and the signatures of those responsible for the analysis.
podrobne podatke o laboratoriju, datum analize in podpis njenih odgovornih oseb.
Chromatogram of the products of the silanisation reaction obtained by the action of lipase on a refined olive oil with 20 % esterified oil added (100 %)
Kromatogram proizvodov reakcije silaniziranja, dobljenih z delovanjem lipaze na rafiniranem oljčnem olju, ki mu je dodanih 20 % 100 % zaestrenega olja
unesterified olive oil, after lipase; after silanisation; under these conditions (8-12 m capillary column) the wax fraction is eluted at the same time as the diglyceride fraction or slightly afterwards.
nezaestrenega oljčnega olja po delovanju lipaze, in silaniziranega; pri teh pogojih (kapilarna kolona 8–12 m) frakcija voskov eluira hkrati s frakcijo diacilglicerolov ali malo zatem.
After lipase, the triglyceride content should not exceed 15 %
Vsebnost triacilglicerolov po lipazi ne sme preseči 15 %.
1 Free fatty acids
1 Proste maščobne kisline
2 Monoglycerides
2 Monogliceridi
3 Diglycerides
3 Digliceridi
4 Triglycerides
4 Trigliceridi
Triglyceride C54
Triacilglicerol C54
unesterified oil after lipase; after silanisation; under these conditions (8-12 m capillary column) the wax fraction is eluted at the same time as the diglyceride fraction or slightly afterwards.
zaestrenega olja po delovanju lipaze; po silaniziranju; pri teh pogojih (kapilarna kolona 8–12 m) frakcija voskov eluira hkrati s frakcijo diglicerida ali malo zatem.
After lipase, the triglyceride content should not exceed 15 %.
Vsebnost trigliceridov po lipazi ne sme preseči 15 %
triglyceride
Triglicerid C54
Note 1.
Opomba 1.
PREPARATION OF THE LIPASE
PRIPRAVA LIPAZE
Lipases with satisfactory activity are commercially available.
Lipaze z zadostno aktivnostjo so komercialno dostopne.
They can also be prepared in the laboratory in the following manner:
Lahko jih pripravimo tudi v laboratoriju, in sicer na naslednji način:
Stir the paste with 2,5 litres of anhydrous acetone for 4-6 hours, then centrifuge.
To tekočino 4 do 6 ur mešamo z 2,5 litra brezvodnega acetona in nato centrifugiramo.
Extract the residue three more times with the same volume of anhydrous acetone, then twice with an acetone/diethyl ether mixture (1/1 v/v) and twice with diethyl ether.
Izvleček naredimo še trikrat z enako količino acetona, nato dvakrat z mešanico acetona/dietilnega etra (1/1) (V/V) in dvakrat z dietilnim etrom.
Vacuum-dry the residue for 48 hours to obtain a stable powder which can be stored for a long time in a refrigerator away from moisture.
Preostanek 48 ur sušimo v vakuumu, da dobimo stabilen prah, ki ga je treba dolgo časa hraniti v hladilniku in pred vlago.
Note 2.
Opomba 2.
MONITORING LIPASE ACTIVITY
PREVERJANJE AKTIVNOSTI LIPAZE
Prepare an olive oil emulsion as follows:
Oljno emulzijo pripravimo na naslednji način:
In a mixer stir for 10 minutes a mixture of 165 ml of a 100 g/l gum arabic solution, 15 g of crushed ice and 20 ml of a previously neutralised olive oil.
V mešalniku 10 minut mešamo mešanico 165 ml raztopine gumarabikuma (100 g/l), 15 g zdrobljenega ledu in 20 ml predhodno nevtraliziranega oljčnega olja.
Pour 10 ml of the emulsion into a 50 ml beaker, then 0,3 ml of a 0,2 g/ml sodium cholate solution and then 20 ml of distilled water.
V čašo prostornine 50 ml zaporedoma damo 10 ml te emulzije, nato 0,3 ml raztopine natrijevega holata (0,2 g/ml) in 20 ml destilirane vode.
Put the beaker in a thermostat set at 37 °C; introduce the electrodes of the pH meter and the screw agitator.
Čašo damo v termostat, naravnan na 37 °C; namestimo elektrode pH metra in spiralni mešalnik.
Using a burette, add a 0,1 N sodium hydroxide solution drop by drop until a pH of 8,3 is obtained.
Z bireto po kapljicah dodajamo raztopino natrijevega hidroksida 0,1 N, dokler ne dobimo pH vrednosti 8,3.
Add an aliquot of the lipase powder suspension in water (0,1 g/ml of lipase).
Dodamo ustrezno količino v vodi raztopljene lipaze v prahu (0,1 g/ml lipaze).
As soon as the pH meter reads 8,3, start the chronometer and add the sodium hydroxide solution drop by drop at a rate which maintains the pH at 8,3.
Takoj ko pH meter pokaže pH 8,3, sprožimo štoparico in po kapljah dodajamo raztopino natrijevega hidroksida, in sicer s tako hitrostjo, da ohranimo pH vrednost 8,3.
Note every minute the volume of solution consumed.
Vsako minuto odčitamo volumen porabljene raztopine.
Record the data on an x/y graph with the time on the x-axis and millilitres of 0,1 N alkaline solution consumed to keep a constant pH on the y-axis.
Podatke zabeležimo v sistem koordinatnih osi, in sicer odčitke časa navedemo kot absciso, kot ordinato pa ml alkalne raztopine 0,1 N, ki smo jih porabili za ohranitev konstantnega pH.
A linear graph should be obtained.
Dobiti moramo linearen graf.
Lipase activity, expressed in lipase units per mg, is given by the following formula:
Aktivnost lipaze, izmerjena v lipaznih enotah na mg, je izražena z naslednjo formulo:
A is activity in lipase units/mg
A aktivnost v lipaznih enotah/mg
V is the number of millilitres of 0,1 N sodium hydroxide solution per minute (calculated on the basis of the graph)
V število ml raztopine natrijevega hidroksida 0,1 N na minuto (izračunano iz grafa)
N is the titre of the sodium hydroxide solution
N normalnost raztopine natrijevega hidroksida
m is the mass in mg of the test lipase.
m masa vzorca lipaze v mg.
A lipase unit is defined as the quantity of enzyme which releases 10 micro-equivalents of acid per minute.’;
Lipazna enota je opredeljena kot količina encima, ki sprosti 10 mikro-ekvivalentov kisline na minuto.“;