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Uvod: Čiščenje posode je vsakodnevno opravilo v gospodinjstvu, ki mu velika večina ljudi ne namenja posebne pozornosti. Le malokdo pred uporabo detergenta prebere navodila za uporabo, ampak detergent dozira po lastnem občutku. Tako lahko čistilno sredstvo predoziramo in s tem povečamo količino ostankov na posodi, kar lahko škodljivo vpliva na naše zdravje. Namen: Namen magistrskega dela je določiti koncentracijo ostankov površinsko aktivne snovi natrijevega dodecil sulfata in biocida 1,2-benzizotiazol-3(2H)-ona na posodi po ročnem čiščenju, ugotoviti, ali hrapavost materiala ter globina posode vplivata na koncentracijo ostankov teh dveh kemikalij na posodi ter preveriti, ali imata v izbranih koncentracijah škodljive učinke na testne organizme. Metode dela: Koncentracijo natrijevega dodecil sulfata smo določili s pomočjo spektrofotometra po dodatku metilenskega modrila, medtem ko smo za določanje 1,2-benzizotiazol-3(2H)-ona uporabili tekočinski kromatograf. Po ugotovljenih koncentracijah ostankov obeh kemičnih snovi smo s pomočjo instrumenta LUMIstox izmerili njuno strupenost na luminiscenčne bakterije Vibrio fischeri. Rezultati: Rezultati so pokazali, da na površini krožnikov in lončkov iz lesa ostane več natrijevega dodecil sulfata in 1,2-benzizotiazol-3(2H)-ona kot na površini krožnikov in lončkov iz plastike, porcelana, nerjaveče pločevine in stekla. Ostanki natrijevega dodecil sulfata so bili na površini lončkov v povprečju za 30 % višji od koncentracije ostankov na površini krožnikov, ostanki 1,2-benzizotiazol-3(2H)-ona pa so za 60 % višji pri lončkih. Tako smo potrdili, da je več ostankov na bolj hrapavih površinah in na globljih posodah. S strupenostnim testom smo ugotovili, da koncentracija ostankov natrijevega dodecil sulfata po ročnem čiščenju povzroči od 1,7 % do 2,8 % zaviranja luminiscence pri bakterijah Vibrio fischeri, koncentracija ostankov 1,2-benzizotiazol-3(2H)-ona pa od 7,1 % do 11,5 % zaviranje luminiscence. Največjo strupenost smo zaznali pri koncentraciji obeh snovi, ki je bila v banjici, v kateri smo prali posodo (99 % zaviranje luminiscence). Razprava in zaključek: Zaradi povečanega adsorbiranja ostankov detergenta na površino posode na bolj hrapavih površinah in na globljih posodah predlagamo, da posodo po čiščenju dobro speremo z večjo količino vode, saj bomo s tem odstranili večji delež ostankov čistilnega sredstva z njene površine. Doziranje detergenta je potrebno upoštevati po navodilih proizvajalca, saj edino tako lahko preprečimo škodljive vplive na zdravje človeka. Introduction: Cleaning dishes is a daily activity in every household, which does not receive special attention by most people. Only a few of them actually read the instructions before using the detergent and usually people do not dose it. In such cases, the misusage of the cleaning agent could lead to elevated amounts of residues on the dishes, that could have some harmful effects on our health. Purpose: The purpose of our research was to determine the residual amount of surfactants – sodium dodecyl sulphate and 1,2-benzisothiazol-3(2H)-one on different materials after manual dishwashing. Besides, it was our task also to study the effect of roughness of the material on the amount and toxicity of sodium dodecyl sulphate and 1,2-benzisothiazol-3(2H)-one. Methods: To determine the amount of residue of sodium dodecyl sulphate a spectrophotometric method employing methylene blue was applied, whereas for the 1,2-benzisothiazol-3(2H)-one determination high performance liquid chromatography was used. After determining the residues of both chemicals, the toxicity measurements were done by LUMIstox instrument by measuring the toxicity of residues on luminescent Vibrio fischeri bacteria. Results: The results showed that on the wooden plate and cup there were higher residues of both sodium dodecyl sulphate and 1,2-benzisothiazol-3(2H)-one, compared to other materials like: plastic, porcelain, stainless steel and glass plate and/or cup. The residues of sodium dodecyl sulphate were on average higher by 30 % on cups, compared to plates while residues of 1,2-benzisothiazol-3(2H)-one were higher by 60 %. That proved that the rougher is the material and the deeper is the dish, the more residues remain on them. The amount of remaining sodium dodecyl sulphate on dishes after manual dishwashing caused from 1,7 % to 2,8 % inhibition of luminescence of Vibrio fischeri bacteria, while the amount of 1,2-benzisothiazol-3(2H)-one caused 7,1 % to 11,5 % inhibition. The highest percent of luminescence inhibition (99 %) was detected in the water in which the dishes were washed indicating the synergistic effect of inhibition of both compounds 1,2-benzisothiazol-3(2H)-one and sodium dodecyl sulphate, which are usually discharged in normal household waste waters. Discussion and conclusion: Due to higher detergent and biocide residues in case of rougher materials and deeper dishes, it is suggested that higher volumes of water are used for the final washing procedure, since this will result in removing a larger portion of the cleaning agent from the surface of the dish. The key element is also the dosing of detergent which should be done according to the instructions from the manufacturer. In this way, some side harmful effects on public health from dishwashing could be avoided.

Namen diplomskega dela je bil določiti kritično micelarno koncentracijo (CMC) anionskega surfaktanta natrijev dodecil sulfat (SDS) in kationskega surfaktanta cetildimetilbenzilamonijev klorid (CDBACl) pri standardnih pogojih in proučiti vpliv temperature na vrednost CMC. Kot topilo smo uporabili Milli-Q vodo. Izbrano temperaturno območje je bilo med 283 K in 323 K. Meritve smo izvedli pri sedmih različnih temperaturah v prej omenjenem temperaturnem območju. Pri tem smo uporabili klasično konduktometrično metodo. Na osnovi grafične predstavitve, CMC v odvisnosti od temperature, smo v skladu z literaturo dobili krivuljo v obliki črke U, kar pomeni, da obstaja minimalna vrednost CMC za posamezni surfaktant pri določeni temperaturi. Na koncu smo izračunali še standardne termodinamske količine: stopnjo disociacije proti-iona (β), spremembo standardne entalpije micelizacije (〖ΔH〗_mic^°), spremembo standardne entropije micelizacije (〖ΔS〗_mic^°) in spremembo standardne proste Gibbsove energije (〖ΔG〗_mic^°). To smo naredili v skladu z dvema enačbama, ki se razlikujeta po tem, da ena vpliv temperature na stopnjo disociacije proti-iona β upošteva v celoti, druga pa ta vpliv na β zanemari. Stopnja disociacije proti-iona s temperaturo narašča. Ta ugotovitev velja za izbrano temperaturno območje in za oba izbrana surfaktanta. Standardna prosta Gibbsova energija micelizacijeje negativna (in glede na izbrano temperaturno območje skoraj konstantna), kar pove, da je proces micelizacije spontan proces. Purpose of this study was to determine the critical micelle concentration (CMC) of the anion surfactant named sodium dodecyl sulphate (SDS) and cationic surfactant cetyldimethylbenzilammonium chloride (CDBACl) under standard conditions. Moreover, the effect of the temperature on the CMC value was also investigated. The Milli-Q water was used as a solvent. Measurements were performed at different temperatures within the temperature range of 283 - 323 K. As measurement method the classical conductivity measurements were used. Using graphs CMC as a function of temperature are consistent with the literature given curve U-shaped, which means that there is a minimum value of the CMC for each surfactant at a given temperature. In the end the standard thermodynamic quantity: degree of counterion dissociation (β), standard enthalpy of micellization (〖ΔH〗_mic^°), standard entropy of micellization (〖ΔS〗_mic^°) and the standard Gibbs free energy (〖ΔG〗_mic^°) were calculated. This was done in accordance with the equations, which differ in that one the effect of temperature on the degree of counterion dissociation β takes into consideration as whole the other this effect ignores. It was found that degree of counterion dissociation increased with increasing temperature (within chosen temperature range) for both SDS and CDBACl. The values for standard Gibbs free energy are negative and almost constant within chosen temperature range, which indicates that the micellization process is spontaneous process for presented system.