natgillin/translations-raw huggingface dataset:
Rinse the separating funnel and the filter with 50 ml light petroleum (3.2), make up to the mark with light petroleum (3.2) and mix well.
Lij ločnik in filter se spereta s 50 ml petroletra (3.2), dopolni se do oznake s petroletrom (3.2) in dobro premeša.
Extraction using an extraction apparatus (4.8)
Ekstrakcija z uporabo naprave za ekstrakcijo (4.8)
When the layers have separated (see observation 7.3) replace the stopper of the glass cylinder (4.8.1) by the ground glass insert (4.8.2) and position the U-shaped lower end of the adjustable tube so that it is just above the level of the interface.
Ko se plasti ločijo (glej opombo 7.3), se zamašek steklenega valja (4.8.1) zamenja z vložkom iz brušenega stekla (4.8.2), spodnji del nastavljive cevi pa se namesti v obliki črke U tik nad raven vmesnika.
By application of pressure from a nitrogen line to the side-arm, transfer the upper light petroleum-layer to a 1000 ml separating funnel (4.2.3).
S tlakom, ki ga tvori dušik v stranski ročici, se zgornja plast petroletra prenese v 1000-mililitrski lij ločnik (4.2.3).
Add 100 ml light petroleum (3.2) to the glass cylinder, stopper and shake well.
V stekleni valj se doda 100 ml petroletra (3.2), zamaši se in dobro pretrese.
Allow the layers to separate and transfer the upper layer to the separating funnel as before.
Počaka se, da se plasti ločijo, zgornja plast pa se prenese v lij ločnik tako kot prej.
Repeat the extraction procedure with further 100 ml of light petroleum (3.2), then twice with 50 ml portions of light petroleum (3.2) and add the light petroleum layers to the separating funnel.
Postopek ekstrakcije se ponovi s 100 ml petroletra (3.2), nato dvakrat s po 50 ml petroletra (3.2), plasti petroletra pa se dodajo v lij ločnik.
Wash the combined light petroleum extracts as described in 5.3.1 and proceed as described there.
Združeni ekstrakti petroletra se sperejo, kakor je opisano v točki 5.3.1, nato pa se nadaljuje, kakor je navedeno v navedeni točki.
Preparation of the sample solution for HPLC
Priprava raztopine vzorca za HPLC
Pipette an aliquot portion of the light petroleum solution (from 5.3.1 or 5.3.2) into a 250 ml pear shaped flask (4.2.4).
Alikvot raztopine petroletra (iz točke 5.3.1 ali 5.3.2) se odpipetira v 250-mililitrsko hruškasto bučko (4.2.4).
Evaporate the solvent nearly to dryness on the rotary evaporator (4.1) with reduced pressure at a bath temperature not exceeding 40 oC.
Topilo se upari skoraj do suhega v rotacijskem uparjalniku (4.1) pri znižanem tlaku in temperaturi kopeli do 40 oC.
Restore atmospheric pressure by admitting nitrogen (3.10) and remove the flask from the rotary evaporator.
Atmosferski tlak se vzpostavi z dovajanjem dušika (3.10), bučka pa se odstrani iz rotacijskega uparjalnika.
Remove the remaining solvent with a stream of nitrogen (3.10) and dissolve the residue immediately in a known volume (10-100 ml) of methanol (3.3) (the concentration of vitamin A must be in the range of 5 IU/ml to 30 IU/ml).
Preostalo topilo se odstrani v toku dušika (3.10), ostanek pa se takoj raztopi v znanem volumnu (10–100 ml) metanola (3.3) (koncentracija vitamina A mora biti 5–30 IU/ml).
Determination by HPLC
Določanje s HPLC
Vitamin A is separated on a C18 reversed phase column (4.5.1) and the concentration is measured by means of a UV detector (325 nm) or a fluorescence detector (excitation: 325 nm, emission: 475 nm) (4.5.2).
Vitamin A se loči na koloni C18 z reverzno fazo (4.5.1), koncentracija pa se izmeri z UV-detektorjem (325 nm) ali fluorescenčnim detektorjem (ekscitacija: 325 nm, emisija: 475 nm) (4.5.2).
Inject an aliquot portion (e.g. 20 μl) of the methanolic solution obtained in 5.4 and elute with the mobile phase (3.9).
Vbrizga se alikvot (npr. 20 μl) raztopine metanola, ki nastane pri točki 5.4, in eluira z mobilno fazo (3.9).
Calculate the mean peak height (area) of several injections of the same sample solution and the mean peak heights (areas) of several injections of the calibration solutions (5.6.2).
Izračuna se srednja vrednost višine (površine) vrhov za več vbrizgov iste raztopine vzorca in srednje vrednosti višin (površin) vrhov za več vbrizgov raztopin za umerjanje (5.6.2).
HPLC conditions
Pogoji za HPLC
The following conditions are offered for guidance; other conditions may be used provided that they give equivalent results.
Naslednji pogoji se lahko uporabljajo kot smernica; lahko se uporabljajo tudi drugi pogoji, če zagotavljajo enakovredne rezultate.
Liquid chromatographic column (4.5.1):
Kolona za tekočinsko kromatografijo (4.5.1):
250 mm × 4 mm, C18, 5 or 10 μm packing, or equivalent
250 mm × 4 mm, C18, polnitev 5 ali 10 μm ali enakovredna
Mobile phase (3.9):
Mobilna faza (3.9):
Mixture of methanol (3.3) and water e.g. 980 + 20 (v + v).
Mešanica metanola (3.3) in vode, npr. 980 + 20 (v + v).
UV detector (325 nm) or fluorescence detector
UV-detektor (325 nm) ali fluorescenčni detektor
(excitation: 325 nm/emission: 475 nm)
(ekscitacija: 325 nm/emisija: 475 nm)
Preparation of the working standard solutions
Priprava delovnih standardnih raztopin
Pipette 20 ml of the vitamin A acetate stock solution (3.11.1) or 20 ml of the vitamin A palmitate stock solution (3.12.1) into a 500 ml flat bottom or conical flask (4.2.1) and hydrolyse as described under 5.2, but without addition of BHT.
20 ml osnovne raztopine acetata vitamina A (3.11.1) ali 20 ml osnovne raztopine palmitata vitamina A (3.12.1) se odpipetira v 500-mililitrsko bučko z ravnim dnom ali erlenmajerico (4.2.1) ter hidrolizira, kakor je navedeno v točki 5.2, vendar brez dodatka BHT.
Subsequently extract with light petroleum (3.2) according to 5.3 and make up to 500 ml with light petroleum (3.2).
Nato se ekstrahira s petroletrom (3.2) v skladu s točko 5.3 in dopolni do 500 ml s petroletrom (3.2).
Evaporate 100 ml of this extract on the rotary evaporator (see 5.4) nearly to dryness, remove the remaining solvent with a stream of nitrogen (3.10) and redissolve the residue in 10,0 ml of methanol (3.3).
100 ml tega ekstrakta se upari v rotacijskem uparjalniku (glej 5.4) skoraj do suhega, odstrani se preostalo topilo s tokom dušika (3.10), ostanek pa se ponovno raztopi v 10,0 ml metanola (3.3).
The nominal concentration of this solution is 560 IU vitamin A per ml.
Nominalna koncentracija te raztopine je 560 IU vitamina A na ml.
The exact content has to be determined according to 5.6.3.3.
Točno vsebnost je treba določiti v skladu s točko 5.6.3.3.
The working standard solution has to be freshly prepared before use.
Delovno standardno raztopino je treba pripraviti svežo pred uporabo.
Pipette 2,0 ml of this working standard solution into a 20 ml graduated flask, make up to the mark with methanol (3.3) and mix.
2,0 ml te delovne standardne raztopine se odpipetira v 20-mililitrsko merilno bučko, dopolni se z metanolom (3.3) do oznake in premeša.
The nominal concentration of this diluted working standard solution is 56 IU vitamin A per ml.
Nominalna koncentracija te razredčene delovne standardne raztopine je 56 IU vitamina A na ml.
Preparation of the calibration solutions and calibration graph
Priprava raztopin za umerjanje in umeritvena krivulja
Transfer 1,0, 2,0, 5,0 and 10,0 ml of the diluted working standard solution into a series of 20 ml graduated flasks, make up to the mark with methanol (3.3) and mix.
1,0, 2,0, 5,0 in 10,0 ml razredčene delovne standardne raztopine se prenese v serijo 20-mililitrskih merilnih bučk, dopolni se z metanolom (3.3) do oznake in premeša.
The nominal concentrations of these solutions are 2,8, 5,6, 14,0 and 28,0 IU vitamin A per ml.
Nominalne koncentracije teh raztopin so 2,8, 5,6, 14,0 in 28,0 IU vitamina A na ml.
Inject 20 μl of each calibration solution several times and determine the mean peak heights (areas).
Večkrat se vbrizga 20 μl vsake raztopine za umerjanje, nato pa se določijo srednje vrednosti višin (površin) vrhov.
Using the mean peak heights (areas) plot a calibration graph considering the results of the UV control (5.6.3.3).
Iz srednjih vrednosti višin (površin) vrhov se pripravi umeritvena krivulja ob upoštevanju rezultatov UV-kontrole (5.6.3.3).
UV standardisation of the standard solutions
UV-standardizacija standardnih raztopin
Vitamin A acetate stock solution
Osnovna raztopina acetata vitamina A
Pipette 2,0 ml of the vitamin A acetate stock solution (3.11.1) into a 50 ml graduated flask (4.2.2) and make up to the mark with 2-propanol (3.8).
2,0 ml osnovne raztopine acetata vitamina A (3.11.1) se odpipetira v 50 ml merilno bučko (4.2.2) in dopolni z 2-propanolom (3.8) do oznake.
The nominal concentration of this solution is 56 IU vitamin A per ml.
Nominalna koncentracija te raztopine je 56 IU vitamina A na ml.
Pipette 3,0 ml of this diluted vitamin A acetate solution into a 25 ml graduated flask and make up to the mark with 2-propanol (3.8).
3,0 ml te razredčene raztopine acetata vitamina A se odpipetira v 25-mililitrsko merilno bučko in dopolni z 2-propanolom (3.8) do oznake.
The nominal concentration of this solution is 6,72 IU vitamin A per ml.
Nominalna koncentracija te raztopine je 6,72 IU vitamina A na ml.
Measure the UV spectrum of this solution against 2-propanol (3.8) in the spectrophotometer (4.6) between 300 nm and 400 nm.
Izmeri se UV-spekter te raztopine proti 2-propanolu (3.8) v spektrofotometru (4.6) med 300 in 400 nm.
The extinction maximum must be between 325 nm and 327 nm.
Maksimalna ekstinkcija mora biti med 325 in 327 nm.
Calculation of the vitamin A content:
Izračun vsebnosti vitamina A:
IU vitamin A/ml = E326 × 19,0
IU vitamina A/ml = E326 × 19,0
for vitamin A acetate = 1530 at 326 nm in 2-propanol)
za acetat vitamina A = 1530 pri 326 nm v 2-propanolu)
Vitamin A palmitate stock solution
Osnovna raztopina palmitata vitamina A
Pipette 2,0 ml of the vitamin A palmitate stock solution (3.12.1) into a 50 ml graduated flask (4.2.2) and make up to the mark with 2-propanol (3.8).
2,0 ml osnovne raztopine palmitata vitamina A (3.12.1) se odpipetira v 50-mililitrsko merilno bučko (4.2.2) in dopolni z 2-propanolom (3.8) do oznake .
Pipette 3,0 ml of this diluted vitamin A palmitate solution into a 25 ml graduated flask and make up to the mark with 2-propanol (3.8).
3,0 ml te razredčene raztopine palmitata vitamina A se odpipetira v 25-mililitrsko merilno bučko in dopolni z 2-propanolom (3.8) do oznake.
for vitamin A palmitate = 957 at 326 nm in 2-propanol)
za palmitat vitamina A = 957 pri 326 nm v 2-propanolu)
Vitamin A working standard solution
Delovna standardna raztopina vitamina A
Pipette 3,0 ml of the undiluted vitamin A working standard solution, prepared according to 5.6.1 into a 50 ml graduated flask (4.2.2) and make up to the mark with 2-propanol (3.8).
3,0 ml nerazredčene delovne standardne raztopine vitamina A, pripravljene v skladu s točko 5.6.1, se odpipetira v 50-mililitrsko merilno bučko (4.2.2) in dopolni z 2-propanolom (3.8) do oznake.
Pipette 5,0 ml of this solution into a 25 ml graduated flask and make up to the mark with 2-propanol (3.8).
5,0 ml te raztopine se odpipetira v 25-mililitrsko merilno bučko in dopolni z 2-propanolom (3.8) do oznake .
IU vitamin A/ml = E325 × 18,3
IU vitamina A/ml = E325 × 18,3
for vitamin A alcohol = 1821 at 325 nm in 2-propanol)
za vitamin A alkohol = 1821 pri 325 nm v 2-propanolu)
Calculation of the results
Izračun rezultatov
From the mean height (area) of the vitamin A peaks of the sample solution determine the concentration of the sample solution in IU/ml by reference to the calibration graph (5.6.2).
Iz srednje vrednosti višin (površin) vrhov vitamina A iz raztopine vzorca se s pomočjo umeritvene krivulje (5.6.2) določi koncentracija raztopine vzorca v IU/ml.
The vitamin A content w in IU/kg of the sample is given by the following formula:
Vsebnost vitamina A (w) v vzorcu, izražena v IU/kg, se izračuna po naslednji formuli:
in which:
pri čemer je:
c vitamin A concentration of the sample solution (5.4) in IU/ml
c koncentracija vitamina A (5.4) v IU/ml v raztopini vzorca;
volume of sample solution (5.4) in ml
volumen raztopine vzorca (5.4) v ml;
volume of aliquot taken in 5.4 in ml
volumen alikvota, uporabljenega pri točki 5.4, v ml;
m weight of the test portion in g
m masa preskusnega vzorca v gramih.
For samples with low vitamin A concentration it may be useful to combine the light petroleum-extracts of two saponification-charges (amount weighed: 25 g) to one sample solution for HPLC-determination.
Pri vzorcih z nizko koncentracijo vitamina A se ekstrakte petroletra iz dveh umilitvenih šarž (natehtana količina: 25 g) lahko združi v eno raztopino vzorca za določanje s HPLC.
The weight of the sample taken for the analysis shall not contain more than 2 g fat.
Masa vzorca za analizo ne vsebuje več kot 2 g maščobe.
If phase separation does not occur add approximately 10 ml ethanol (3.1) to break the emulsion.
Če se fazi ne ločita, se doda približno 10 ml etanola (3.1) za razbitje emulzije.
With cod-liver oil and other pure fats the saponification time shall be extended to 45-60 minutes.
Pri ribjem olju in drugih čistih maščobah se čas umiljenja podaljša na 45–60 minut.
Hydroquinone can be used instead of BHT.
Namesto BHT se lahko uporablja hidrokinon.
Using a normal phase-column the separation of retinol isomers is possible.
Z običajno fazno kolono je možno ločiti izomere retinola.
But in that case, the heights (areas) of all cis and trans isomers peaks have to be summed for calculations.
Vendar je pri tem treba za izračune zabeležiti vse višine (površine) vrhov vseh cis in trans izomerov.
Approximately 150 mg ascorbic acid can be used instead of sodium ascorbate solution.
Namesto raztopine natrijevega askorbata se lahko uporabi približno 150 mg askorbinske kisline.
Approximately 50 mg EDTA can be used instead of sodium sulphide solution.
Namesto raztopine natrijevega sulfida se lahko uporabi približno 50 mg EDTA.
In cases of analysis of vitamin A in milk replacers, specific attention has to be paid
Pri analizi vitamina A v mlečnih nadomestkih je treba paziti:
at saponification (5.2): due to the amount of fat present in the sample, increasing of potassium hydroxide solution amount (3.4) may be necessary,
pri umiljenju (5.2): zaradi količine maščobe v vzorcu je lahko potrebna večja količina raztopine kalijevega hidroksida (3.4),
at extraction (5.3): due to the presence of emulsions, adaptation of the water/ethanol 2:1 ratio may be necessary.
pri ekstrakciji (5.3): zaradi prisotnosti emulzij je morda potrebna sprememba razmerja voda/etanol 2:1.
To check if the applied method of analysis generates reliable results on this specific matrix (milk replacer), a recovery test shall be applied on an additional test portion.
Da se preveri, ali uporabljena analitska metoda zagotavlja zanesljive rezultate glede te specifične matrice (mlečni nadomestek), je treba na dodatnem preskusnem vzorcu izvesti preskus izkoristka.
If the recovery rate is lower than 80 %, the analytical result has to be corrected for recovery.
Če je izkoristek nižji od 80 %, se pri analitskem rezultatu uporabi popravek za izkoristek.
The difference between the results of two parallel determinations carried out on the same sample must not exceed 15 % relative to the higher result.
Razlika med rezultatoma dveh vzporednih določanj, izvedenih na istem vzorcu, ne sme presegati 15 % najvišjega rezultata.
Premix feed
Krma in premiksi
Mineral concentrate
Mineralni koncentrat
Protein feed
Beljakovinska krma
Piglet
Krma za prašiče
mean [IU/kg]
Srednja vrednost [IU/kg]
L number of laboratories
L število laboratorijev;
n number of single values
n število posameznih vrednosti;
coefficient of variation of repeatability
koeficient variacije ponovljivosti;
coefficient of variation of reproducibility.
koeficient variacije obnovljivosti.
Figure 1: Extraction apparatus (4.8)
Slika 1: Naprava za ekstrakcijo (4.8)
Glass cylinder (4.8.1)
Stekleni valj (4.8.1)
(height approximately 48 cm)
(približna višina 48 cm)
Ground glass insert (4.8.2)
Vložek iz brušenega stekla (4.8.2)
(length approximately 45 cm)
(približna višina 45 cm)
Adjustable tube
Nastavljiva cev
saponified feed
umiljena polnitev
DETERMINATION OF VITAMIN E
DOLOČANJE VITAMINA E
This method makes it possible to determine the level of vitamin E in feed and premixtures.
Ta metoda omogoča določanje ravni vitamina E v krmi in premiksih.
The content of vitamin E is expressed as mg DL-α-tocopherol acetate per kg.
Vsebnost vitamina E se izrazi v mg acetata DL-α-tokoferola na kg.
1 mg DL-α-tocopherol acetate corresponds to 0,91 mg DL-α-tocopherol (vitamin E).
1 mg acetata DL-α-tokoferola ustreza 0,91 mg DL-α-tokoferola (vitamina E).
The limit of quantification is 2 mg vitamin E/kg.
Meja kvantifikacije je 2 mg vitamina E/kg.
This limit of quantification is only achievable with fluorescence detector.
Ta meja kvantifikacije se lahko doseže le s fluorescenčnim detektorjem.
With an UV detector the limit of quantification is 10 mg/kg.
Meja kvantifikacije za UV-detektor je 10 mg/kg.
The sample is hydrolysed with ethanolic potassium hydroxide solution and the vitamin E is extracted into light petroleum.
Vzorec se hidrolizira z raztopino etanolnega kalijevega hidroksida, vitamin E pa se ekstrahira v petroleter.
The content of vitamin E is determined by reversed phase high performance liquid chromatography (RP-HPLC) using a fluorescence or a UV detector.
Vsebnost vitamina E se določi s tekočinsko kromatografijo visoke ločljivosti z reverzno fazo (RP–HPLC) z uporabo UV- ali fluorescenčnega detektorja.
Light petroleum, boiling range 40 oC-60 oC.
Petroleter, vrelišče 40–60 oC
Potassium hydroxide solution, c = 50 g/100 ml.
Raztopina kalijevega hidroksida, c = 50 g/100 ml
Sodium ascorbate solution, c = 10 g/100 ml (see 7.7 observations).
Raztopina natrijevega askorbata, c = 10 g/100 ml (glej opombo 7.7)
Sodium sulphide, Na2S· x H2O (x = 7-9).
Natrijev sulfid, Na2S· x H2O (x = 7–9)
Sodium sulphide solution, c = 0,5 mol/l in glycerol, β = 120 g/l. (for x = 9) (see 7.8 observations)
Raztopina natrijevega sulfida, c = 0,5 mol/l v glicerolu, β = 120 g/l (za x = 9) (glej opombo 7.8)
Phenolphthalein solution, c = 2 g/100 ml in ethanol (3.1).
Raztopina fenolftaleina, c = 2 g/100 ml v etanolu (3.1)
Nitrogen, oxygen free.
Dušik, brez kisika
DL-α-tocopherol acetate, extra pure, of certified activity.
Acetat DL-α-tokoferola, posebne čistosti, certificirane aktivnosti
Stock solution of DL-α-tocopherol acetate: Weigh to the nearest 0,1 mg, 100 mg of DL-α-tocopherol acetate (3.10) into a 100 ml graduated flask.
Osnovna raztopina acetata DL-α-tokoferola: 100 mg acetata DL-α-tokoferola (3.10) se natehta na 0,1 mg natančno in prenese v 100-mililitrsko merilno bučko.
Dissolve in ethanol (3.1) and make up to the mark with the same solvent.
Raztopi se v etanolu (3.1) in dopolni z istim topilom do oznake.
1 ml of this solution contains 1 mg DL-α-tocopherol acetate.
1 ml te raztopine vsebuje 1 mg acetata DL-α-tokoferola.
(UV control see 5.6.1.3; stabilisation see 7.4 observations).
(Za UV-kontrolo glej točko 5.6.1.3, za stabilizacijo pa opombo 7.4.)
DL-α-tocopherol, extra pure, of certified activity.
DL-α-tokoferol, posebne čistosti, certificirane aktivnosti
Stock solution of DL-α-tocopherol: Weigh to the nearest 0,1 mg, 100 mg of DL-α-tocopherol (3.10) into a 100 ml graduated flask.
Osnovna raztopina acetata DL-α-tokoferola: 100 mg DL-α-tokoferola (3.10) se natehta na 0,1 mg natančno in prenese v 100-mililitrsko merilno bučko.
1 ml of this solution contains 1 mg DL-α-tocopherol.
1 ml te raztopine vsebuje 1 mg DL-α-tokoferola.
(UV control see 5.6.2.3; stabilisation see 7.4 observations).
(Za UV-kontrolo glej točko 5.6.2.3, za stabilizacijo pa opombo 7.4.)
2,6-Di-tert-butyl-4-methylphenol (BHT) (see 7.5 observations).
2,6-Di-tert-butil-4-metilfenol (BHT) (glej opombo 7.5)
Rotary film evaporator.
Rotacijski uparjalnik
Amber glassware.
Temna steklovina
Flat bottom or conical flasks, 500 ml, with ground-glass socket.
Bučke z ravnim dnom ali erlenmajerice, 500-mililitrske, z brušenim vratom
Graduated flasks with ground-glass stoppers, narrow-necked, 10, 25, 100 and 500 ml.
Merilne bučke z zamaški iz brušenega stekla, z ozkim vratom, 10-, 25-, 100- in 500-mililitrske
Separating funnels, conical, 1000 ml, with ground-glass stoppers.
Liji ločniki, konusni, 1000-mililitrski, z zamaški iz brušenega stekla
Pear shaped flasks, 250 ml, with ground-glass sockets.
Hruškaste bučke, 250-mililitrske, z zamaški iz brušenega stekla
Allihn condenser, jacket length 300 mm, with ground-glass joint, with adapter for gas feed pipe.
Allihnov kondenzator, dolžina obroča 300 mm, s spojem iz brušenega stekla in nastavkom za dovodno cev plina
Pleated filter paper for phase separation, diameter 185 mm (e.g. Schleicher & Schuell 597 HY 1/2).
Naguban filtrirni papir za ločevanje faz, premera 185 mm (npr. Schleicher & Schuell 597 HY 1/2)
HPLC equipment with injection system.
Oprema za kromatografijo HPLC s sistemom vbrizgavanja
Liquid chromatographic column, 250 mm × 4 mm, C18, 5 or 10 μm packing, or equivalent.
Kolona za tekočinsko kromatografijo, 250 mm x 4 mm C18, polnitev 5 ali 10 μm ali enakovredna
Fluorescence or UV detector, with variable wavelength adjustment.
Fluorescenčni ali UV-detektor, s spremenljivo nastavitvijo valovne dolžine
Spectrophotometer with 10 mm quartz cells.
Spektrofotometer z 10 mm kvarcnimi kivetami
Water-bath with magnetic stirrer.
Vodna kopel z magnetnim mešalnikom
Glass cylinder of 1 l capacity fitted with a ground glass neck and stopper.
steklenega valja z volumnom l litra, vratom iz brušenega stekla in zamaškom;
Vitamin E is sensitive to (UV-) light and to oxidation.
Vitamin E je občutljiv na (UV) svetlobo in oksidacijo.
Grinding must be carried out immediately before weighing and saponification otherwise there may be losses of vitamin E.
Drobljenje se mora izvesti neposredno pred tehtanjem in umiljenjem, drugače lahko pride do izgube vitamina E.
Depending on the vitamin E content weigh, to the nearest 0,01 g, 2 g to 25 g of the sample into a 500 ml flat bottom or conical flask (4.2.1).
Glede na vsebnost vitamina E se natehta 2–25 g vzorca na 0,01 g natančno in prenese v 500-mililitrsko bučko z ravnim dnom ali erlenmajerico (4.2.1).
Add successively with swirling 130 ml ethanol (3.1), approximately 100 mg BHT (3.12), 2 ml sodium ascorbate solution (3.5) and 2 ml sodium sulphide solution (3.6).
Med obračanjem se postopoma dodajo 130 ml etanola (3.1), približno 100 mg BHT (3.12), 2 ml raztopine natrijevega askorbata (3.5) in 2 ml raztopine natrijevega sulfida (3.6).
Fit the condenser (4.3) to the flask and immerse the flask in a water-bath with magnetic stirrer (4.7).
Na bučko se namesti kondenzator (4.3), bučka pa se potopi v vodno kopel z magnetnim mešalnikom (4.7).
Then add 25 ml potassium hydroxide solution (3.4) through the condenser (4.3) and allow to reflux for a further 25 min. with stirring under a slow stream of nitrogen.
Nato se skozi kondenzator (4.3) doda 25 ml raztopine kalijevega hidroksida (3.4) in z mešanjem pod rahlim pretokom dušika pusti pod kondenzatorjem povratnega toka nadaljnjih 25 minut.
Restore atmospheric pressure by admitting nitrogen (3.9) and remove the flask from the rotary evaporator.
Atmosferski tlak se vzpostavi z dovajanjem dušika (3.9), bučka pa se odstrani iz rotacijskega uparjalnika.
Remove the remaining solvent with a stream of nitrogen (3.9) and dissolve the residue immediately in a known volume (10-100 ml) of methanol (3.3) (the concentration of DL-α-tocopherol must be in the range 5 μg/ml to 30 μg/ml).
Preostalo topilo se odstrani v toku dušika (3.9), ostanek pa se takoj raztopi v znanem volumnu (10–100 ml) metanola (3.3) (koncentracija DL-α-tokoferola mora biti 5–30 μg/ml).
Vitamin E is separated on a C18 reversed phase column (4.5.1) and the concentration is measured using a fluorescence detector (excitation: 295 nm, emission: 330 nm) or a UV detector (292 nm) (4.5.2).
Vitamin E se loči na koloni C18 z reverzno fazo (4.5.1), koncentracija pa se izmeri s fluorescenčnim detektorjem (ekscitacija: 295 nm, emisija: 330 nm) ali UV-detektorjem (292 nm) (4.5.2).
Inject an aliquot portion (e.g. 20 μl) of the methanolic solution obtained in 5.4 and elute with the mobile phase (3.8).
Vbrizga se alikvot (npr. 20 μl) raztopine metanola, ki nastane pri točki 5.4, in eluira se z mobilno fazo (3.8).