natgillin/translations-raw huggingface dataset:
the limitation of a maximum concentration in either phase of 0,01 mol per litre.
omejitvijo največje koncentracije v kateri koli fazi na 0,01 mola na liter.
Three tests are carried out.
Opravijo se trije preskusi.
In the first, the calculated volume ratio of n-octanol to water is used; in the second, this ratio is divided by two; and in the third, this ratio is multiplied by two (e.g. 1:1, 1:2, 2:1).
Pri prvem se uporabi izračunano volumsko razmerje n-oktanol/voda; pri drugem se to razmerje deli z dve; pri tretjem pa se pomnoži z dve (npr. 1:1, 1:2, 2:1).
A stock solution is prepared in n-octanol pre-saturated with water.
Pripravi se osnovna raztopina v n-oktanolu, predhodno nasičenem z vodo.
The concentration of this stock solution should be precisely determined before it is employed in the determination of the partition coefficient.
Preden se ta osnovna raztopina uporabi za določanje porazdelitvenega koeficienta, je treba natančno določiti njeno koncentracijo.
This solution should be stored under conditions which ensure its stability.
Ta raztopina se hrani v pogojih, ki zagotavljajo njeno stabilnost.
The test temperature should be kept constant (± 1 oC) and lie in the range of 20 to 25 oC.
Temperatura preskusa mora biti konstantna (± 1 oC) in v območju med 20 in 25 oC.
Establishment of the partition equilibrium
Vzpostavitev porazdelitvenega ravnotežja
Duplicate test vessels containing the required, accurately measured amounts of the two solvents together with the necessary quantity of the stock solution should be prepared for each of the test conditions.
Za vsakega od preskusnih pogojev je treba pripraviti po dve preskusni posodi, ki vsebujeta potrebni, točno odmerjeni količini obeh topil ter potrebno količino osnovne raztopine.
The n-octanol phases should be measured by volume.
Faze n-oktanola se merijo z volumni.
The test vessels should either be placed in a suitable shaker or shaken by hand.
Preskusne posode je treba bodisi namestiti na ustrezne stresalnike ali jih stresati ročno.
When using a centrifuge tube, a recommended method is to rotate the tube quickly through 180o about its transverse axis so that any trapped air rises through the two phases.
Kadar se uporabljajo centrifugirke, je priporočena metoda hitro obračanje centrifugirke za 180o okrog njene prečne osi, tako da se morebitni ujeti zrak dvigne skozi obe fazi.
Experience has shown that 50 such rotations are usually sufficient for the establishment of the partition equilibrium.
Izkušnje so pokazale, da 50 takšnih obratov običajno zadostuje za vzpostavitev porazdelitvenega ravnotežja.
To be certain, 100 rotations in five minutes are recommended.
Za večjo gotovost pa se priporoča 100 obratov v petih minutah.
Phase separation
Ločitev faz
When necessary, in order to separate the phases, centrifugation of the mixture should be carried out.
Kadar je potrebno, se fazi ločita s centrifugiranjem.
This should be done in a laboratory centrifuge maintained at room temperature, or, if a non-temperature controlled centrifuge is used, the centrifuge tubes should be kept for equilibration at the test temperature for at least one hour before analysis.
To se opravi z laboratorijsko centrifugo, v kateri se vzdržuje sobna temperatura, če pa se uporabi centrifuga brez termostata, se centrifugirke pustijo najmanj eno uro pred analizo pri temperaturi preskusa, da se vzpostavi ravnotežje.
For the determination of the partition coefficient, it is necessary to determine the concentrations of the test substance in both phases.
Za določitev porazdelitvenega koeficienta je treba določiti koncentracijo preskusne snovi v obeh fazah.
This may be done by taking an aliquot of each of the two phases from each tube for each test condition and analyzing them by the chosen procedure.
To se lahko stori tako, da se vzame alikvot vsake izmed dveh faz iz vsake epruvete za vsak preskusni pogoj in se analizira po izbranem postopku.
The total quantity of substance present in both phases should be calculated and compared with the quantity of the substance originally introduced.
Izračunati je treba skupno količino snovi v obeh fazah in jo primerjati s prvotno vneseno količino snovi.
The aqueous phase should be sampled by a procedure that minimises the risk of including traces of n-octanol: a glass syringe with a removable needle can be used to sample the water phase.
Vzorec vodne faze je treba odvzeti s postopkom, ki kar se da zmanjša tveganje, da bi se v njem pojavile sledi n-oktanola: v ta namen se lahko uporabi steklena brizga z zamenljivo iglo.
The syringe should initially be partially filled with air.
Brizga se najprej delno napolni z zrakom.
Air should be gently expelled while inserting the needle through the n-octanol layer.
Ta zrak se počasi iztiska med potiskanjem igle skozi plast n-oktanola.
An adequate volume of aqueous phase is withdrawn into the syringe.
V brizgo se vsrka primeren volumen vodne faze.
The syringe is quickly removed from the solution and the needle detached.
Brizga se hitro potegne iz raztopine in igla se odstrani.
The contents of the syringe may then be used as the aqueous sample.
Vsebina brizge se nato lahko uporabi kot vodni vzorec.
The concentration in the two separated phases should preferably be determined by a substance-specific method.
Koncentracija v obeh ločenih fazah se po možnosti določi z metodo, ki je najbolj primerna za posamezno snov.
Examples of analytical methods which may be appropriate are:
Primeri morebitnih ustreznih analitskih metod so:
photometric methods,
fotometrične metode,
gas chromatography,
plinska kromatografija,
high-performance liquid chromatography.
tekočinska kromatografija visoke ločljivosti.
A liquid chromatograph, fitted with a pulse-free pump and a suitable detection device, is required.
Potrebujemo tekočinski kromatograf, opremljen s črpalko s stabilnim pretokom in ustreznim detektorjem.
The use of an injection valve with injection loops is recommended.
Priporoča se uporaba injektorja z injicirnimi zankami.
The presence of polar groups in the stationary phase may seriously impair the performance of the HPLC column.
Prisotnost polarnih skupin v stacionarni fazi lahko resno zmanjša učinkovitost kolone HPLC.
Therefore, stationary phases should have the minimal percentage of polar groups (11).
Zato mora imeti stacionarne faze le minimalni odstotek polarnih skupin (11).
Commercial microparticulate reverse-phase packings or ready-packed columns can be used.
Lahko se uporabijo na trgu dostopna polnila za mikro kolone z reverzno fazo ali že pripravljene kolone.
A guard column may be positioned between the injection system and the analytical column.
Med injektorskim sistemom in analitsko kolono se lahko namesti predkolona.
HPLC grade methanol and HPLC grade water are used to prepare the eluting solvent, which is degassed before use.
Topilo za eluiranje se pripravi iz metanola za HPLC in vode za HPLC ter pred uporabo razplini.
Isocratic elution should be employed.
Uporabiti je treba izokratsko elucijo.
Methanol/water ratios with a minimum water content of 25 % should be used.
Uporabiti je treba razmerja metanol/voda z deležem vode najmanj 25 %.
Typically a 3:1 (v/v) methanol-water mixture is satisfactory for eluting compounds of log P 6 within an hour, at a flow rate of 1 ml/min.
Običajno je zmes metanol/voda v razmerju 3:1 (v/v) zadovoljiva za eluiranje snovi z log P 6 v eni uri pri pretoku 1 ml/min.
For compounds of high log P it may be necessary to shorten the elution time (and those of the reference compounds) by decreasing the polarity of the mobile phase or the column length.
Pri snoveh z večjo vrednostjo log P bo morda treba skrajšati elucijski čas (in elucijski čas referenčnih snovi) z zmanjšanjem polarnosti mobilne faze ali podaljšanjem kolone.
Substances with very low solubility in n-octanol tend to give abnormally low log Pow values with the HPLC method; the peaks of such compounds sometimes accompany the solvent front.
Snovi z zelo majhno topnostjo v n-oktanolu dajo pri metodi HPLC velikokrat nenormalno majhne vrednosti log Pow; vrhove takih snovi včasih spremlja fronta topila.
This is probably due to the fact that the partitioning process is too slow to reach the equilibrium in the time normally taken by an HPLC separation.
To se verjetno zgodi zato, ker je porazdelitveni proces prepočasen, da bi dosegla ravnotežje v času, ki je običajno potreben za ločitev s HPLC.
Decreasing the flow rate and/or lowering the methanol/water ratio may then be effective to arrive at a reliable value.
V takem primeru je lahko učinkovit način za dosego zanesljive vrednosti zmanjšanje pretoka in/ali razmerja metanol/voda.
Test and reference compounds should be soluble in the mobile phase in sufficient concentrations to allow their detection.
Preskusne in referenčne snovi morajo biti topne v mobilni fazi v zadostnih koncentracijah, da je omogočena njihova detekcija.
Only in exceptional cases may additives be used with the methanol-water mixture, since additives will change the properties of the column.
Dodatki v zmesi metanol/voda se lahko uporabijo le izjemoma, saj spremenijo lastnosti kolone.
For chromatograms with additives it is mandatory to use a separate column of the same type.
Za kromatograme z dodatki je obvezna uporaba ločene kolone enake vrste.
If methanol-water is not appropriate, other organic solvent-water mixtures call be used, e.g. ethanol-water or acetonitrile-water.
Če zmes metanol/voda ni primerna, se lahko uporabijo druge zmesi organsko topilo/voda, npr. etanol/voda ali acetonitril/voda.
The pH of the eluent is critical for ionisable compounds.
Pri snoveh, ki disociirajo na ione, je pH eluenta zelo pomemben.
It should be within the operating pH range of the column, which is usually between 2 and 8.
Mora biti v delovnem območju pH kolone, ki je običajno med 2 in 8.
Buffering is recommended.
Priporoča se dodajanje pufra.
Care must be taken to avoid salt precipitation and column deterioration which occur with some organic phase/buffer mixtures.
Preprečiti je treba obarjanje soli in razpadanje kolone, ki lahko nastaneta pri nekaterih zmeseh organske faze in pufra.
HPLC measurements with silica-based stationary phases above pH 8 are not advisable since the use of an alkaline, mobile phase may cause rapid deterioration in the performance of the column.
Meritve HPLC s stacionarnimi fazami z osnovo iz silicijevega dioksida in pH nad 8 niso priporočljive, saj uporaba alkalne mobilne faze lahko povzroči hitro poslabšanje učinkovitosti kolone.
Solutes
Topljenci
The reference compounds should be the purest available.
Referenčne snovi morajo biti čim bolj čiste.
Compounds to be used for test or calibration purposes are dissolved in the mobile phase if possible.
Snovi, ki se bodo uporabile za preskus ali umerjanje, se po možnosti raztopijo v mobilni fazi.
The temperature during the measurements should not vary by more than ± 2 K.
Med merjenjem se temperatura ne sme spreminjati za več kot ± 2 K.
Calculation of dead time to
Izračun mrtvega časa to
The dead time to can be determined by using either a homologous series (e.g. n-alkyl methyl ketones) or unretained organic compounds (e.g. thiourea or formamide).
Mrtvi čas to se lahko določi z uporabo bodisi homolognih vrst (npr. n-alkilmetil-ketoni) bodisi z organskimi spojinami, ki se ne zadržijo v koloni (npr. tiosečnina ali formamid).
For calculating the dead time to by using a homologous series, a set of at least seven members of a homologous series is injected and the respective retention times are determined.
Za izračun mrtvega časa to z uporabo homolognih vrst se injicira niz najmanj sedmih spojin homologne vrste in določijo njihovi retenzijski časi.
The raw retention times tr (nc + 1) are plotted as a function of tr(nc) and the intercept a and slope b of the regression equation:
Izriše se krivulja dobljenih retenzijskih časov tr(nc + 1) v odvisnosti od tr(nc) ter določita presek, a, in naklon, b, regresijske enačbe:
tr(nc + 1) = a + b tr(nc)
tr(nc+1) = a + btr(nc)
are determined (nc = number of carbon atoms).
(nc = število ogljikovih atomov).
The dead time to is then given by:
Mrtvi čas to je določen z:
Calibration graph
Umeritvena krivulja
The next step is to construct a correlation plot of log k values versus log p for appropriate reference compounds.
Naslednji korak je izdelava krivulje vrednosti log k v odvisnosti od log P za ustrezne referenčne snovi.
In practice, a set of between 5 and 10 standard reference compounds whose log p is around the expected range are injected simultaneously and the retention times are determined, preferably on a recording integrator linked to the detection system.
V praksi to pomeni, da se hkrati injicira 5 do 10 standardnih referenčnih snovi, katerih log P je blizu pričakovanega območja, in določijo retenzijski časi, po možnosti na integratorju zapisovalniku, povezanem z detektorjem.
The corresponding logarithms of the capacity factors, log k, are calculated and plotted as a function of the log p determined by the shake-flask method.
Izračunajo se ustrezni logaritmi faktorjev kapacitete, log k, in nariše se krivulja log k v odvisnosti od log P, določenega z metodo stresanja bučke.
The calibration is performed at regular intervals, at least once daily, so that possible changes in column performance can be allowed for.
Umerjanje se izvaja redno, najmanj enkrat dnevno, tako da se lahko upoštevajo morebitne spremembe v delovanju kolone.
Determination of the capacity factor of the test substance
Določanje faktorja kapacitete preskusne snovi
The test substance is injected in as small a quantity of mobile phase as possible.
Preskusna snov se injicira v najmanjšo možno količino mobilne faze.
The retention time is determined (in duplicate), permitting the calculation of the capacity factor k. From the correlation graph of the reference compounds, the partition coefficient of the test substance can be interpolated.
Določi se retenzijski čas (z dvema vzporednima meritvama), ki omogoča izračun faktorja kapacitete k. Iz korelacijske krivulje za referenčne snovi se lahko interpolira porazdelitveni koeficient preskusne snovi.
For very low and very high partition coefficients, extrapolation is necessary.
Pri zelo majhnih in zelo velikih porazdelitvenih koeficientih je potrebna ekstrapolacija.
In those cases particular care has to be taken of the confidence limits of the regression line.
V takih primerih je treba še posebej upoštevati meje zaupanja regresijske premice.
The reliability of the determined values of P can be tested by comparison of the means of the duplicate determinations with the overall mean.
Zanesljivost določenih vrednosti P je mogoče preskusiti s primerjanjem srednjih vrednosti vzporednih določitev s skupno srednjo vrednostjo.
when the methods are not applicable (e.g. surface active material), a calculated value or an estimate based on the individual n-octanol and water solubilities should be provided,
kadar metode niso uporabne (npr. pri površinsko aktivnih snoveh), je treba navesti izračunano vrednost ali oceno na podlagi topnosti v n-oktanolu in topnosti v vodi,
all information and remarks relevant for the interpretation of results, especially with regard to impurities and physical state of the substance.
vse informacije in opombe, pomembne za razlago rezultatov, zlasti glede nečistot in agregatnega stanja snovi.
For shake-flask method:
Za metodo stresanja bučke:
the result of the preliminary estimation, if any,
rezultat predhodne ocene, če je bila opravljena,
temperature of the determination,
temperatura določanja,
data on the analytical procedures used in determining concentrations,
podatki o uporabljenih analitskih postopkih za določanje koncentracij,
time and speed of centrifugation, if used,
čas in hitrost centrifugiranja, če je bilo uporabljeno,
the measured concentrations in both phases for each determination (this means that a total of 12 concentrations will be reported),
izmerjene koncentracije v obeh fazah za vsako določitev (to pomeni, da bo v poročilu skupaj 12 koncentracij),
the weight of the test substance, the volume of each phase employed in each test vessel and the total calculated amount of test substance present in each phase after equilibration,
masa preskusne snovi, volumen vsake faze, uporabljene v vsaki posodi, in izračunana skupna količina preskusne snovi v vsaki fazi po vzpostavitvi ravnotežja,
the calculated values of the partition coefficient (P) and the mean should be reported for each set of test conditions as should the mean for all determinations.
izračunane vrednosti porazdelitvenega koeficienta (P) in njihova srednja vrednost za vsak sklop preskusnih pogojev ter srednja vrednost vseh določitev.
If there is a suggestion of concentration dependency of the partition coefficient, this should be noted in the report,
Če kar koli kaže na odvisnost porazdelitvenega koeficienta od koncentracije, je to treba vključiti v poročilo,
the standard deviation of individual P values about their mean should be reported,
standardna deviacija posameznih vrednosti P od njihove srednje vrednosti,
the mean P from all determinations should also be expressed as its logarithm (base 10),
srednja vrednost P vseh določitev mora biti izražena tudi z logaritmom (osnova 10),
the calculated theoretical Pow when this value has been determined or when the measured value is > 104,
izračunana teoretična vrednost Pow, če je bila določena, ali če je izmerjena vrednost > 104,
pH of water used and of the aqueous phase during the experiment,
pH uporabljene vode in vodne faze med preskusom,
if buffers are used, justification for the use of buffers in place of water, composition, concentration and pH of the buffers, pH of the aqueous phase before and after the experiment.
če se uporabijo pufri, utemeljitev uporabe pufrov namesto vode, sestavo, koncentracijo in pH pufrov ter pH vodne faze pred in po preskusu.
For HPLC method:
Za metodo HPLC:
test and reference substances, and their purity,
preskusna in referenčne snovi ter njihova čistost,
temperature range of the determinations,
temperaturno območje določitev,
pH at which the determinations are made,
pH, pri katerem so bile opravljene določitve,
details of the analytical and guard column, mobile phase and means of detection,
podatki o analitski koloni in predkoloni, mobilni fazi ter načinu detekcije,
retention data and literature log P values for reference compounds used in calibration,
podatki o retenziji in vrednosti log P iz literature za referenčne snovi, uporabljene za umerjanje,
details of fitted regression line (log k versus log P),
podatki o prilagojeni regresijski premici (log k v odvisnosti od log P),
average retention data and interpolated log P value for the test compound,
podatki o povprečni retenziji in interpolirana vrednost log P za preskusno snov,
description of equipment and operating conditions,
opis opreme in delovnih pogojev,
elution profiles,
elucijski diagrami,
quantities of test and references substances introduced in the column,
količine preskusne in referenčnih snovi, vnesene v kolono,
dead-time and how it was measured.
mrtvi čas in kako je bil izmerjen.
Available from Pomona College Medical Chemistry Project 1982, Pomona College, Claremont, California 91711.
–Available from Pomona College Medical Chemistry Project 1982, Pomona College, Claremont, California 91711.
Jubermann, Verteilen und Extrahieren, in Methoden der Organischen Chemie (Houben Weyl), Allgemeine Laboratoriumpraxis (edited by E. Muller), Georg Thieme Verlag, Stuttgart, 1958, Band I/1, p. 223-339.
Jubermann, Verteilen und Extrahieren, in Methoden der Organischen Chemie (Houben Weyl), Allgemeine Laboratoriumpraxis (edited by E.Muller), Georg Thieme Verlag, Stuttgart, 1958, Band I/1, 223–339.
Martin, Quantitative Drug Design, Marcel Dekker, New York, Base1, 1978.
Martin, Quantitative Drug Design, Marcel Dekker, New York, Base 1, 1978.
Calculation/estimation methods
Računske/ocenjevalne metode
A general introduction to calculation methods, data and examples are provided in the Handbook of Chemical Property Estimation Methods (a).
Splošni uvod v računske metode, podatki in primeri so na voljo v Priročniku metod za ocenjevanje kemijskih lastnosti (a).
Calculated values of Pow can be used:
Izračunane vrednosti Pow se lahko uporabijo:
for deciding which of the experimental methods is appropriate (shake-flask range: log Pow: - 2 to 4, HPLC range: log Pow: 0 to 6),
za izbiro primerne preskusne metode (območje metode stresanja bučke: log Pow : –2 do 4, območje HPLC: log Pow: 0 do 6),
for selecting the appropriate test conditions (e.g. reference substances for HPLC procedures, volume ratio n-octanol/water for shake flask method),
za izbiro ustreznih pogojev preskusa (npr. referenčne snovi za postopke HPLC, volumsko razmerje n-oktanol/voda za metodo stresanja bučke),
as a laboratory internal check on possible experimental errors,
kot notranje laboratorijsko preverjanje za odkrivanje možnih napak preskusa,
for providing a Pow-estimate in cases where the experimental methods cannot be applied for technical reasons.
za določitev ocene vrednosti Pow, kadar preskusnih metod ni mogoče uporabiti zaradi tehničnih razlogov.
The value of the partition coefficient can be estimated by the use of the solubilities of the test substance in the pure solvents: For this:
Vrednost porazdelitvenega koeficienta se lahko oceni na podlagi topnosti preskusne snovi v čistih topilih:Za to:
Pestimate
Pocena
= saturation cn-octanol
= nasičenje cn-oktanol
saturation cwater
nasičenje cvoda
CALCULATION METHODS
RAČUNSKE METODE
Principle of the calculation methods
Princip računskih metod
Lists of fragment constants and correction terms ate available (b)(c)(d)(e);.
Na voljo so seznami konstant fragmentov in členov korekcije (b)(c)(d)(e).
Some are regularly updated (b).
Nekateri se redno dopolnjujejo (b).
In general, the reliability of the calculation method decreases with increasing complexity of the compound under study.
Na splošno se zanesljivost računske metode manjša z večjo kompleksnostjo preučevane snovi.
In the case of simple molecules with low molecular weight and one or two functional groups, a deviation of 0,1 to 0,3 log Pow units between the results of the different fragmentation methods and the measured value can be expected.
Pri enostavnih molekulah z majhno molsko maso in eno ali dvema funkcionalnima skupinama se lahko pričakuje odstopanje za 0,1 do 0,3 enote log Pow med rezultati različnih metod fragmentacije in izmerjeno vrednostjo.
In the case of more complex molecules the margin of error can be greater.
Pri bolj kompleksnih molekulah je območje napake lahko večje.
This will depend on the reliability and availability of fragment constants, as well as on the ability to recognise intramolecular interactions (e.g. hydrogen bonds) and the correct use of the correction terms (less of a problem with the computer software CLOGP-3) (b).
To je odvisno od zanesljivosti in razpoložljivosti konstant fragmentov ter od zmožnosti prepoznavanja intramolekularnih interakcij (npr. vodikove vezi) in pravilne uporabe členov korekcije (manj težavno z računalniško programsko opremo CLOGP-3) (b).
In the case of ionising compounds the correct consideration of the charge or degree of ionisation is important.
Pri snoveh, ki se lahko ionizirajo, je pomembno, da se pravilno upošteva naboj ali stopnja ionizacije.
Calculation procedures
Računski postopki
Hansch π-method
Hanschova p-metoda
The original hydrophobic substituent constant, π, introduced by Fujira et al.
Izvirna konstanta hidrofobnih substituentov, π, ki jo je vpeljal Fujira et al.
is defined as:
je opredeljen kot:
where Pow (PhX) is the partition coefficient of an aromatic derivative and Pow (PhH) that of the parent compound
pri čemer je Pow (PhX) porazdelitveni koeficient aromatskega derivata in Pow (PhH) porazdelitveni koeficient izhodne spojine
(e.g. πCl = log Pow (C6H5Cl) - log Pow (C6H6) = 2,84 - 2,13 = 0,71).
(npr. πCl = log Pow (C6H5Cl) - log Pow (C6H6) = 2,84 - 2,13 = 0,71).
According to its definition the π-method is applicable predominantly for aromatic substitution. π-values for a large number of substituents have been tabulated (b)(c)(d).
Glede na svojo opredelitev je π-metoda uporabna predvsem za aromatsko substitucijo. Pripravljene so bile tabele π-vrednosti za veliko število substituentov (b)(c)(d).