natgillin/translations-raw huggingface dataset:
This solubilising agent: (a) should be miscible with water such as methanol or acetonitrile; (b) its concentration should not exceed 1 % of the total volume of the stock solution and should constitute less than that in the solution of the test substance which will come in contact with the soil (preferably less than 0,1 %); and (c) should not be a surfactant or undergo solvolytic reactions with the test chemical.
To topilo: (a) naj bo tako, ki se meša z vodo, kot sta metanol ali acetonitril; (b) njegova koncentracija naj ne presega 1 % skupne prostornine osnovne raztopine in naj bo manjša od te koncentracije v raztopini preskusne snovi, ki bo prišla v stik s tlemi (najbolje manj kot 0,1 %); in (c) naj ne bo površinsko aktivna snov in naj ne bo podvrženo solvoliznim reakcijam s preskusno kemikalijo.
The use of a solubilising agent should be stipulated and justified in the reporting of the data.
Uporabo topila je treba navesti in utemeljiti pri poročanju o podatkih.
Another alternative for poorly soluble substances is to add the test substance to the test system by spiking: the test substance is dissolved in an organic solvent, an aliquot of which is added to the system of soil and 0,01 M solution of CaCl2 in distilled or de-ionised water.
Druga možnost za slabo topne snovi je dodajanje preskusne snovi v preskusni sistem s primešanjem: preskusna snov se raztopi v organskem topilu, katerega alikvot se doda sistemu tal in 0,01 M raztopine CaCl2 v destilirani ali deionizirani vodi.
The content of organic solvent in the aqueous phase should be kept as low as possible, normally not exceeding 0,1 %.
Vsebnost organskega topila v vodni fazi naj bo čim manjša in naj normalno ne presega 0,1 %.
Spiking from an organic solution may suffer from volume unreproducibility.
Težava pri primešanju iz organske raztopine je lahko neponovljivost glede prostornine.
Thus, an additional error may be introduced as the test substance and co-solvent concentration would not be the same in all tests.
Tako lahko pride do dodatne napake, ker koncentracije preskusne snovi in pomožnega topila ne bodo enake pri vseh preskusih.
PREREQUISITES FOR PERFORMING THE ADSORPTION/DESORPTION TEST
PREDPOGOJI ZA IZVEDBO PRESKUSA ADSORPCIJE/DESORPCIJE
The analytical method
Analitska metoda
The key parameters that can influence the accuracy of sorption measurements include the accuracy of the analytical method in analysis of both the solution and adsorbed phases, the stability and purity of the test substance, the attainment of sorption equilibrium, the magnitude of the solution concentration change, the soil/solution ratio and changes in the soil structure during the equilibration process (35)(59-62).
Ključni parametri, ki lahko vplivajo na točnost meritev sorpcije, zajemajo točnost analitske metode pri analiziranju faze raztopine in adsorbirane faze, stabilnost in čistost preskusne snovi, doseganje sorpcijskega ravnotežja, velikost spremembe koncentracije raztopine, razmerje tla/raztopina in spremembe strukture tal med procesom uravnoteženja (35) (59–62).
Some examples bearing upon the accuracy issues are given in Appendix 2.
Nekaj primerov v zvezi z vprašanjem točnosti je navedenih v Dodatku 2.
The reliability of the analytical method used must be checked at the concentration range which is likely to occur during the test.
Zanesljivost uporabljene analitske metode je treba preveriti pri območju koncentracij, ki se bodo verjetno pojavile v preskusu.
The experimenter should feel free to develop an appropriate method with appropriate accuracy, precision, reproducibility, detection limits and recovery.
Izvajalec poskusa naj svobodno razvije ustrezno metodo z ustrezno točnostjo, natančnostjo, ponovljivostjo, mejami detekcije in rekuperacijo.
Guidance on how to perform such a test is given by the experiment below.
Smernice za izvedbo takega preskusa so dane s spodnjim poskusom.
An appropriate volume of 0,01 M CaCl2, e.g. 100 cm3, is agitated during 4 h with a weight of soil, e.g. 20 g, of high adsorbability, i.e. with high organic carbon and clay content; these weights and volumes may vary depending on analytical needs, but a soil/solution ratio of 1:5 is a convenient starting point.
Ustrezna prostornina 0,01 M CaCl2, npr. 100 cm3, se stresa 4 h z določeno količino, npr. 20 g, tal z visoko adsorptivnostjo t.j. tal z veliko vsebnostjo organskega ogljika in gline; te teže in prostornine so lahko različne glede na analitske potrebe, vendar je primerno izhodišče razmerje tla/raztopina 1:5.
The mixture is centrifuged and the aqueous phase may be filtrated.
Zmes se centrifugira in vodna faza se lahko filtrira.
A certain volume of the test substance stock solution is added to the latter to reach a nominal concentration within the concentration range which is likely to occur during the test.
Določena prostornina osnovne raztopine preskusne snovi se doda vodni fazi, da se doseže nominalna koncentracija v območju koncentracij, ki se bodo verjetno pojavile v preskusu.
This volume should not exceed 10 % of the final volume of the aqueous phase, in order to change as little as possible the nature of the pre-equilibration solution.
Ta prostornina naj ne presega 10 % končne prostornine vodne faze, da se narava raztopine pred uravnoteženjem čim manj spremeni.
The solution is analysed.
Raztopina se analizira.
One blank run consisting of the system soil + CaCl2 solution (without test substance) must be included, in order to check for artefacts in the analytical method and for matrix effects caused by the soil.
Vključiti je treba slepi vzorec, ki ga sestavlja sistem tal in raztopine CaCl2 (brez preskusne snovi) za preverjanje artefaktov pri analitski metodi in vplivov matriksa, ki jih povzročijo tla.
The analytical methods which can be used for sorption measurements include gas-liquid chromatography (GLC), high-performance liquid chromatography (HPLC), spectrometry (e.g. GC/mass spectrometry, HPLC/mass spectrometry) and liquid scintillation counting (for radiolabelled substances).
Analitske metode, ki se lahko uporabijo za merjenje sorpcije, zajemajo plinsko-tekočinsko kromatografijo (GLC), tekočinsko kromatografijo visoke ločljivosti (HPLC), spektrometrijo (npr. GC/masna spektrometrija, HPLC/masna spektromertrija) in tekočinsko scintilacijsko štetje (za radioaktivno označene snovi).
Independent of the analytical method used, it is considered suitable if the recoveries are between 90 % and 110 % of the nominal value.
Ne glede na uporabljeno analitsko metodo, velja za primerno, če je rekuperacija med 90 % in 110 %) nominalne vrednosti.
In order to allow for detection and evaluation after partitioning has taken place, the detection limits of the analytical method should be at least two orders of magnitude below the nominal concentration.
Da bi bila po porazdelitvi mogoča detekcija in ovrednotenje, naj bodo meje detekcije analitske metode vsaj dva velikostna reda pod nominalno koncentracijo.
The characteristics and detection limits of the analytical method available for carrying out adsorption studies play an important role in defining the test conditions and the whole experimental performance of the test.
Lastnosti in meje detekcije analitske metode za izvajanje študij adsorpcije imajo pomembno vlogo pri določanju preskusnih pogojev in celotne eksperimentalne izvedbe preskusa.
This method follows a general experimental path and provides recommendations and guidance for alternative solutions where the analytical method and laboratory facilities may impose limitations.
Ta metoda sledi splošni eksperimentalni poti ter daje priporočila in smernice za alternativne rešitve, kadar analitska metoda ali zmožnosti laboratorija omejujejo izvedbo.
The selection of optimal soil/solution ratios
Izbira optimalnih razmerij tla/raztopina
Selection of appropriate soil to solution ratios for sorption studies depends on the distribution coefficient Kd and the relative degree of adsorption desired.
Izbira ustreznih razmerij tla/raztopino za študije sorptivnosti je odvisna od porazdelitvenega koeficienta Kd in želene relativne stopnje adsorpcije.
The change of the substance concentration in the solution determines the statistical accuracy of the measurement based on the form of adsorption equation and the limit of the analytical methodology, in detecting the concentration of the chemical in solution.
Sprememba koncentracije snovi v raztopini določa statistično točnost meritve na osnovi oblike adsorpcijske enačbe in meje analitske metodologije pri zaznavanju koncentracije kemikalije v raztopini.
Therefore, in general practice it is useful to settle on a few fixed ratios, for which the percentage adsorbed is above 20 %, and preferably >50 % (62), while care should be taken to keep the test substance concentration in the aqueous phase high enough to be measured accurately.
Zato je v splošni praksi koristno določiti nekaj fiksnih razmerij, pri katerih je adsorbirani odstotek nad 20 % in najbolje nad 50 % (62), pri tem pa je treba paziti, da je koncentracija preskusne snovi v vodni fazi ves čas dovolj velika, da omogoča točne meritve.
This is particularly important in the case of high adsorption percentages.
To je zlasti pomembno v primeru visokih adsorpcijskih odstotkov.
A convenient approach to selecting the appropriate soil/water ratios, is based on an estimate of the Kd value either by preliminary studies or by established estimation techniques (Appendix 3).
Primeren pristop k izbiranju ustreznih razmerij tla/raztopina temelji na oceni vrednosti Kd s predhodnimi študijami ali po uveljavljenih tehnikah ocenjevanja (Dodatek 3).
Selection of an appropriate ratio can then be made based on a plot of soil/solution ratio versus Kd for fixed percentages of adsorption (Fig.1).
Ustrezno razmerje se nato lahko izbere na podlagi grafičnega prikaza razmerja tla/raztopina v odvisnosti od Kd za fiksne odstotke adsorpcije (slika 1).
In this plot it is assumed that the adsorption equation is linear.
V tem grafičnem prikazu se predpostavlja, da je adsorpcijska enačba linearna.
The applicable relationship is obtained by rearranging equation (4) of the Kd in the form of equation (1):
Uporabna odvisnost se dobi s preureditvijo enačbe (4) za Kd v obliko enačbe (1):
or in its logarithmic form assuming that R = msoil/V0 and Aeq %/100 = ms
ali v njeni logaritemski obliki, ob predpostavki, da R = msoil/V0 and Aeq %/100 = ms
Fig. 1 Relationship between soil to solution ratios and Kd at various percentages of adsorbed test substance
Slika 1: Odvisnost med razmerji tla/raztopina in Kd pri različnih odstotkih adsorbirane preskusne snovi
Soil to Solution Ratio
Razmerje tla/raztopina
Distribution coefficient Kd (cm3 g–1)
Porazdelitveni koeficient kd (cm3 g–1)
Fig. 1 shows soil/solution ratios required as a function of Kd for different levels of adsorption.
Slika 1 prikazuje potrebna razmerja tla/raztopina kot funkcija Kd za različne stopnje adsorpcije.
For example, with a soil/solution ratio of 1:5 and a Kd of 20, approximately 80 % adsorption would occur.
Na primer, pri razmerju tla/raztopina 1:5 in Kd 20 bi prišlo do približno 80-odstotne adsorpcije.
To obtain 50 % adsorption for the same Kd, a 1:25 ratio must be used.
Da bi pri enakem Kd dobili 50-odstotno adsorpcijo, je treba uporabiti razmerje 1:25.
This approach to selecting the appropriate soil/solution ratios gives the investigator the flexibility to meet experimental needs.
Ta pristop k izbiranju ustreznih razmerij tla/raztopina omogoča preiskovalcu fleksibilnost, da lahko zadovolji potrebe preskusa.
Areas which are more difficult to deal with are those where the chemical is highly or very slightly adsorbed.
Težavnejši primeri so tisti, kjer se kemikalija zelo dobro ali zelo slabo adsorbira.
Where low adsorption occurs, a 1:1 soil/solution ratio is recommended, although for some very organic soil types smaller ratios may be necessary to obtain a slurry.
Kadar je adsorpcija nizka, je priporočeno razmerje tla/raztopina 1:1, vendar so pri nekaterih zelo organskih tipih tal lahko potrebna manjša razmerja, da dobimo blato.
Care must be taken with the analytical methodology to measure small changes in solution concentration; otherwise the adsorption measurement will be inaccurate.
Pri analitski metodologiji je potrebna previdnost, da se izmerijo majhne spremembe v koncentraciji raztopine; drugače bo meritev adsorpcije netočna.
On the other hand, at very high distribution coefficients Kd, one can go up to a 1:100 soil/solution ratio in order to leave a significant amount of chemical in solution.
Po drugi strani lahko pri zelo visokih porazdelitvenihih koeficientih Kd uporabimo lahko razmerje tla/raztopina do 1:100, da bi v raztopini ostala pomembna količina kemikalije.
However, care must be taken to ensure good mixing, and adequate time must be allowed for the system to equilibrate.
Vendar je treba paziti, da zagotovimo dobro mešanje, in omogočimo dovolj časa za vzpostavitev ravnotežja v sistemu.
An alternative approach to deal with these extreme cases when adequate analytical methodology is missing, is to predict the Kd value applying estimation techniques based, for example, on Pow values (Appendix 3).
Druga možnost za obvladovanje teh ekstremnih primerov, ko ni primerne analitske metodologije, je napovedovanje vrednosti Kd z uporabo tehnik ocenjevanja, na primer na osnovi vrednosti Pow (Dodatek 3).
This could be useful especially for low adsorbed/polar chemicals with Pow < 20 and for lipophilic/highly sorptive chemicals with Pow > 104.
To je lahko uporabno zlasti pri slabo adsorbiranih/polarnih kemikalijah s Pow < 20 in lipofilnih/zelo sorptivnih kemikalijah s Pow > 104.
All experiments are done at ambient temperature and, if possible, at a constant temperature between 20 oC and 25 oC.
Vsi preskusi se izvedejo pri normalni temperaturi in, če je mogoče, pri stalni temperaturi med 20 in 25 oC.
Centrifugation conditions should allow the removal of particles larger than 0,2 μm from the solution.
Pogoji centrifugiranja morajo omogočati odstranitev delcev iz raztopine, ki so večji od 0,2 μm.
This value triggers the smallest sized particle that is considered as a solid particle, and is the limit between solid and colloid particles.
Ta velikost ustreza najmanjšemu delcu, ki še velja za trden delec, in je meja med trdnimi in koloidnimi delci.
Guidance on how to determine the centrifugation conditions is given in Appendix 4.
Smernice za določitev pogojev centrifugiranja so navedena v Dodatku 4.
If the centrifugation facilities cannot guarantee the removal of particles larger than 0,2 μm, a combination of centrifugation and filtration with 0,2 μm filters could be used.
Če centrifuga ne more zagotoviti odstranitve delcev, večjih od 0,2 μm, se lahko uporabi kombinacija centrifugiranja in filtriranja z 0,2 μm filtri.
These filters should be made of a suitable inert material to avoid any losses of the test substance on them.
Ti filtri naj bodo iz primernega inertnega materiala, da se na njih ne bi izgubljala preskusna snov.
In any case, it should be proven that no losses of the test substance occur during filtration.
V vsakem primeru je treba dokazati, da med filtracijo ne prihaja do izgub preskusne snovi.
Tier 1 — Preliminary study
Stopnja 1 – Predhodna študija
The purpose of conducting a preliminary study has already been given in the Scope section.
Namen predhodne študije je bil že naveden v poglavju Področje uporabe.
Guidance for setting up such a test is given with the experiment suggested below.
Smernice za postavitev takega preskusa pa so dane s spodaj predlaganim preskusom.
Selection of optimal soil/solution ratios
Izbira optimalnih razmerij tla/raztopina
Two soil types and three soil/solution ratios (six experiments) are used.
Uporabita se dva tipa tal in tri razmerja tla/raztopina (šest poskusov).
One soil type has high organic carbon and low clay content, and the other low organic carbon and high clay content.
En tip tal naj ima visoko vsebnost organskega ogljika in nizko vsebnost gline, drugi pa nizko vsebnost organskega ogljika in visoko vsebnost gline.
The following soil to solution ratios are suggested:
Predlagana so naslednja razmerja tla/raztopina:
50 g soil and 50 cm3 aqueous solution of the test substance (ratio 1/1),
50 g tal in 50 cm3 vodne raztopine preskusne snovi (razmerje 1/1),
10 g soil and 50 cm3 aqueous solution of the test substance (ratio 1/5),
10 g tal in 50 cm3 vodne raztopine preskusne snovi (razmerje 1/5),
2 g soil and 50 cm3 aqueous solution of the test substance (ratio 1/25).
2 g tal in 50 cm3 vodne raztopine preskusne snovi (razmerje 1/25).
The minimum amount of soil on which the experiment can be carried out depends on the laboratory facilities and the performance of analytical methods used.
Minimalna količina tal, s katero se lahko izvede poskus, je odvisna od laboratorijskih zmožnosti in učinkovitosti uporabljenih analitskih metod.
However, it is recommended to use at least 1 g, and preferably 2 g, in order to obtain reliable results from the test.
Vendar je priporočljivo uporabiti vsaj 1 g, najbolje pa 2 g, da bi bili rezultati preskusa zanesljivi.
One control sample with only the test substance in 0,01 M CaCl2 solution (no soil) is subjected to precisely the same steps as the test systems, in order to check the stability of the test substance in CaCl2 solution and its possible adsorption on the surfaces of the test vessels.
Kontrolni vzorec samo s preskusno snovjo v 0,01 M raztopini CaCl2 (brez tal) se tretira po natančno enakem postopku kot preskusni sistem, da se preveri stabilnost preskusne snovi v raztopini CaCl2 in njeno morebitno adsorpcijo na površine preskusnih posod.
A blank run per soil with the same amount of soil and total volume of 50 cm30,01 M CaCl2 solution (without test substance) is subjected to the same test procedure.
Po en slepi vzorec na tip tal z enako količino tal in skupno prostornino 50 cm30,01 M raztopine CaCl2 (brez preskusne snovi) se tretirajo po enakem preskusnem postopku.
This serves as a background control during the analysis to detect interfering substances or contaminated soils.
To je namenjeno kontroli ozadja med analizo, da se zaznajo moteče snovi ali kontaminirana tla.
All the experiments, included controls and blanks, should be performed at least in duplicate.
Vse poskuse, vključno s kontrolami in slepimi vzorci, je treba izvajati vsaj v dveh ponovitvah.
The total number of the samples which should be prepared for the study can be calculated with respect to the methodology which will be followed.
Skupno število vzorcev, ki jih je treba pripraviti za študijo, se lahko izračuna glede na metodologijo, ki bo uporabljena.
Methods for the preliminary study and the main study are generally the same, exceptions are mentioned where relevant.
Metode za predhodno študijo in glavno študijo so na splošno enake, kjer je ustrezno, so navedene izjeme.
The air-dried soil samples are equilibrated by shaking with a minimum volume of 45 cm3 of 0,01 M CaCl2 overnight (12 h) before the day of the experiment.
Na zraku posušeni vzorci tal se uravnotežijo s stresanjem s prostornino vsaj 45 cm30,01 M CaCl2 čez noč (12 h) pred dnem preskusa.
Afterwards, a certain volume of the stock solution of the test substance is added in order to adjust the final volume to 50 cm3.
Nato se doda določena količina osnovne raztopine preskusne snovi, da se končna prostornina dopolni do 50 cm3.
This volume of the stock solution added: (a) should not exceed 10 % of the final 50 cm3 volume of the aqueous phase in order to change as little as possible the nature of the pre-equilibration solution; and (b) should preferably result in an initial concentration of the test substance being in contact with the soil (C0) at least two orders of magnitude higher than the detection limit of the analytical method; this threshold safeguards the ability to perform accurate measurements even when strong adsorption occurs (> 90 %) and to determine later the adsorption isotherms.
Ta količina dodane osnovne raztopine: (a) naj ne presega 10 % končne prostornine vodne faze 50 cm3, da se narava raztopine pred uravnoteženjem čim manj spremeni; in (b) naj bo taka, da bo začetna koncentracija preskusne snovi v stiku s tlemi (Co) vsaj dva velikostna reda večja od meje detekcije analitske metode; ta prag omogoča izvajanje točnih meritev, tudi če pride do močne adsorpcije (> 90 %), in kasnejšo določitev adsorpcijskih izoterm.
It is also recommended, if possible, that the initial substance concentration (C0) not exceed half of its solubility limit.
Priporočljivo je tudi, da začetna koncentracija snovi (Co), če je to mogoče, ne presega polovice njene meje topnosti.
An example of how to calculate the concentration of the stock solution (Cst) is given below.
Primer za izračun koncentracije osnovne raztopine (Cst) je naveden spodaj.
A detection limit of 0,01 μg cm-3 and 90 % adsorption are assumed; thus, the initial concentration of the test substance in contact with the soil should preferably be 1 μg cm-3 (two orders of magnitude higher than the detection limit).
Predpostavlja se meja detekcije pri 0,01 ug cm-3 in 90-odstotna adsorpcija; tako, da je najbolje, da je začetna koncentracija preskusne snovi v stiku s tlemi 1 ug cm-3 (dva velikostna reda nad mejo detekcije). Če predpostavljamo, da se doda največja priporočena prostornina osnovne raztopine, t.j.
Supposing that the maximum recommended volume of the stock solution is added, i.e. 5 to 45 cm30,01 M CaCl2 equilibration solution (= 10 % of the stock solution to 50 cm3 total volume of aqueous phase), the concentration of the stock solution should be 10 μg cm-3; this is three orders of magnitude higher than the detection limit of the analytical method.
5 cm3 k 45 cm30,01 M CaCl2 raztopine za uravnoteženje (= 10 % osnovne raztopine v 50 cm3 skupne prostornine vodne faze), bi morala biti koncentracija osnovne raztopine 10 µg cm-3; to je tri velikostne rede nad mejo detekcije analitske metode.
The pH of the aqueous phase should be measured before and after contact with the soil since it plays an important role in the whole adsorption process, especially for ionisable substances.
pH vodne faze se meri pred in po stiku s tlemi, saj ima pomembno vlogo v adsorpcij skem procesu, zlasti pri snoveh, ki lahko ionizirajo.
The mixture is shaken until adsorption equilibrium is reached.
Zmes se stresa, dokler ni vzpostavljeno adsorpcijsko ravnotežje.
The equilibrium time in soils is highly variable, depending on the chemical and the soil; a period of 24 h is generally sufficient (77).
Čas potreben za vzpostavitev ravnotežja v tleh je zelo različen glede na kemikalijo in tip tal; navadno zadostuje 24 h (77).
In the preliminary study, samples may be collected sequentially over a 48 h period of mixing (for example at 4, 8, 24, 48 h).
V predhodni študiji se vzorci lahko zbirajo zaporedno v času 48 h mešanja (na primer po 4, 8, 24, 48 h).
However, times of analysis should be considered with flexibility with respect to the work schedule of the laboratory.
Vendar naj bodo časi analize fleksibilni ob upoštevanju delovnega razporeda v laboratoriju.
There are two options for the analysis of the test substance in the aqueous solution: (a) the parallel method and (b) the serial method.
Za analiziranje preskusne snovi v vodni raztopini obstajata dve možnosti: (a) paralelna metoda in (b) serialna metoda.
It should be stressed that, although the parallel method is experimentally more tedious, the mathematical treatment of the results is simpler (Appendix 5).
Poudariti je treba, da je pri paralelni metodi matematična obdelava rezultatov enostavnejša (Dodatek 5), čeprav je metoda eksperimentalno bolj zahtevna.
However, the choice of the methodology to be followed, is left to the experimenter who will need to consider the available laboratory facilities and resources.
Vendar je izbira metodologije prepuščena izvajalcu, ki mora pretehtati zmožnosti in sredstva laboratorija.
parallel method: samples with the same soil/solution ratio are prepared, as many as the time intervals at which it is desired to study the adsorption kinetics.
Paralelna metoda: pripravijo se vzorci z enakim razmerjem tla/raztopina, toliko vzorcev, kot je časovnih intervalov, pri katerih se želi proučevati kinetiko adsorpcije.