Ewa Olkowska

Analytical procedures for the determination of surfactants in environmental samples

Because of their specific physical and chemical properties (amphiphilicity, solubility in polar and nonpolar liquids, ability to form micelles, adsorption at phase boundaries, low toxicity) surfactants (surface-active compounds) are widely applied in industry and in the household. As their applications are on a very large scale, it has become necessary to acquire a more detailed understanding of their environmental fate. In the methodologies for analysing environmental samples, the isolation and/or preconcentration of analytes constitutes an important step. The usual techniques are liquid-liquid extraction (LLE), solid-phase extraction (SPE - also used for extract clean-up contains following analytes isolated by another technique) or accelerated solvent extraction (ASE). For the analysis of samples/extracts, depending on whether information is required - the total concentration or the levels of particular surface-active compounds in environmental samples - spectrophotometry, tensammetry or electrophoresis, and chromatography may be used. Nowadays, high-performance liquid chromatography (HPLC) is usually coupled with a universal mass spectrometry detector (MS) (or tandem mass spectrometry detector MS-MS), what allows for detection, identification and quantification the various compounds in a particular group of surfactants in suitably prepared solvent extracts.

Occurrence of Surface Active Agents in the Environment

Due to the specific structure of surfactants molecules they are applied in different areas of human activity (industry, household). After using and discharging from wastewater treatment plants as effluent stream, surface active agents (SAAs) are emitted to various elements of the environment (atmosphere, waters, and solid phases), where they can undergo numerous physic-chemical processes (e.g., sorption, degradation) and freely migrate. Additionally, SAAs present in the environment can be accumulated in living organisms (bioaccumulation), what can have a negative effect on biotic elements of ecosystems (e.g., toxicity, disturbance of endocrine equilibrium). They also cause increaseing solubility of organic pollutants in aqueous phase, their migration, and accumulation in different environmental compartments. Moreover, surfactants found in aerosols can affect formation and development of clouds, which is associated with cooling effect in the atmosphere and climate changes. The environmental fate of SAAs is still unknown and recognition of this problem will contribute to protection of living organisms as well as preservation of quality and balance of various ecosystems. This work contains basic information about surfactants and overview of pollution of different ecosystems caused by them (their classification and properties, areas of use, their presence, and behavior in the environment).

A solid phase extraction-ion chromatography with conductivity detection procedure for determining cationic surfactants in surface water samples.

A new analytical procedure for the simultaneous determination of individual cationic surfactants (alkyl benzyl dimethyl ammonium chlorides) in surface water samples has been developed. We describe this methodology for the first time: it involves the application of solid phase extraction (SPE-for sample preparation) coupled with ion chromatography-conductivity detection (IC-CD-for the final determination). Mean recoveries of analytes between 79% and 93%, and overall method quantification limits in the range from 0.0018 to 0.038 μg/mL for surface water and CRM samples were achieved. The methodology was applied to the determination of individual alkyl benzyl quaternary ammonium compounds in environmental samples (reservoir water) and enables their presence in such types of waters to be confirmed. In addition, it is a simpler, less time-consuming, labour-intensive, avoiding use of toxic chloroform and significantly less expensive methodology than previously described approaches (liquid-liquid extraction coupled with liquid chromatography-mass spectrometry).

Determination of Surfactants in Environmental Samples. Part III. Non-Ionic Compounds

Abstract Non-ionic surface active agents are a diverse group of chemicals which have an uncharged polar head and a non-polar tail. They have different properties due to amphiphilic structure of their molecules. Commercial available non-ionic surfactants consist of the broadest spectrum of compounds in comparison with other types of such agents. Typically, non-ionic compounds found applications in households and industry during formulation of cleaning products, cosmetics, paints, preservative coatings, resins, textiles, pulp and paper, petroleum products or pesticides. Their are one of the most common use class of surfactants which can be potential pollution sources of the different compartment of environment (because of they widely application or discharging treated wastewaters to surface water and sludge in agricultural). It is important to investigate the behavior, environmental fate of non-ionic surfactants and their impact on living organisms (they are toxic and/or can disrupt endocrine functions). To solve such problems should be applied appropriated analytical tools. Sample preparation step is one of the most critical part of analytical procedures in determination of different compounds in environmental matrices. Traditional extraction techniques (LLE - for liquid samples; SLE - for solid samples) are time and solvent-consuming. Developments in this field result in improving isolation efficiency and decreasing solvent consumption (eg SPE and SPME - liquid samples or PLE, SFE and MAE - solid samples). At final determination step can be applied spectrophotometric technique, potentiometric titrametration or tensammetry (determination total concentration of non-ionic surfactants) or chromatographic techniques coupled with appropriated detection techniques (individual analytes). The literature data concerning the concentrations of non-ionic surfactants in the different compartments of the environment can give general view that various ecosystems are polluted by those compounds. Abstrakt Niejonowe surfaktanty stanowią zróżnicowaną grupę związków chemicznych, które w swojej budowie zawierają pozbawioną ładunku polarną „głowę” i niepolarny „ogon”. Tego typu związki powierzchniowo czynne ze względu na amfifilową strukturę posiadają różnorodne właściwości. Komercyjnie dostępne produkty zawsze zawierają szerokie spektrum związków o niejonowym charakterze. Niejonowe związki znalazły zastosowanie głównie w gospodarstwach domowych oraz w przemyśle przy wytwarzaniu produktów czyszczących, włókienniczych, celulozowych i papierniczych, kosmetyków, farb, powłok konserwujących, żywic, produktów naftowych i pestycydów. Jest to jedna z najczęściej wykorzystywanych klas surfaktantów, które mogą stanowić potencjalne źródło zanieczyszczenia różnych elementów środowiska (ze względu na ich szerokie zastosowanie lub kierowanie oczyszczonych ścieków do wód powierzchniowych i stosowania osadów czynnych w rolnictwie). Istotne staje się badanie losu środowiskowego substancji powierzchniowo czynnych oraz ich wpływu względem organizmów żywych (ze względu na działanie toksyczne i zdolność do wpływu na funkcje endokrynologiczne). Te zagadnienia mogą być rozwiązywane przez stosowanie odpowiednich narzędzi analitycznych. Etap przygotowania próbek do analizy jest jednym z najważniejszych etapów procedur analitycznych. Tradycyjne techniki ekstrakcji (LLE - dla próbek ciekłych; SLE - dla próbek stałych) cechują się czasochłonnością oraz używaniem dużych ilości rozpuszczalników. Rozwój w tym zakresie doprowadził do poprawy efektywności izolacji analitów oraz zmniejszenia wymaganych objętości rozpuszczalników (np. SPE i SPME - próbki ciekłe lub PLE, SFE i MAE - próbki stałe). Na etapie oznaczania końcowego mogą być wykorzystane: technika spektrofotometryczna, technika miareczkowania potencjometrycznego lub tensammetria (do określania sumarycznego stężenie niejonowych związków powierzchniowoczynnych) oraz techniki chromatograficzne (do określania poziomów stężenie pojedynczych analitów). Analiza danych literaturowych dotyczących stężeń surfaktantów w różnych elementach środowiska pozwala na stwierdzenie, że różne ekosystemy są zanieczyszczone przez związki o charakterze niejonowym.

Assessment of the water quality of Kłodnica River catchment using self-organizing maps

Risk assessment of industrial areas heavily polluted due to anthropogenic actions is of increasing concern worldwide. So is the case of Polish Silesia region where mostly heavy industry like smelters, mining, chemical industries as well as heat and electricity production facilities are being located. Such situation raises numerous questions about environmental state of local water bodies with special attention paid to the Kłodnica Catchment which is receiving waste waters from numerous industrial plants. The efforts have been undertaken to describe the situation (spatial and temporal distribution of pollution) in the area of interest with the help of self-organizing maps - modern non-parametric data mining method - yet still rarely applied in environmental studies where numerous input parameters have to be considered. As a result of studies clear distinction into 3 pollution groups could be obtained as well as the seasonal variation of pollution could be distinguished.

Determination of Surfactants in Environmental Samples. Part I. Cationic Compounds / Oznaczanie Surfaktantów W Próbkach Środowiskowych. Część I. Związki Kationowe

Abstract Compounds from the group of cationic surfactants are widely applied in household, industrial, cleaning, disinfectant, cosmetic and pharmaceutical products as their specific properties (antimicrobial, emulsifying, anticorrosion, softening). After use, cationic surfactants are disposed to wastewater-treatment plants and finally with effluent water to surface waters due to their incomplete degradation. Moreover, they can freely circulate in different environmental compartments including living organisms. It becomes indispensable to recognize in more detail behavior, fate and biological effects of cationic surfactants. This analytical problem can be solved with use sensitive and reliable analytical techniques at sample preparation step and final determination step. In recent years, during isolation analytes from environmental samples mainly were used liquid-liquid extraction (LLE) - liquid matrices or solid-liquid extraction (SLE) - solid matrices. This technique involves application of toxic solvents (chloroform), is time-consuming and interferences are co-extracted. Nowadays, in scientific centers are carried out research to replace this traditional technique. So far, the following techniques were applied: solid-phase extraction (SPE) or it modification (HF-LPME) - liquid samples; accelerated solvent extraction (ASE) and supercritical fluid extraction (SFE) - solid samples. During the determination of total content of cationic surface active agents in environmental samples were used a traditional spectrophotometry technique and potentiometric titration technique. But those techniques are susceptible of interferences on analysis results (anionic and non-ionic compounds). The chromatographic technique (liquid chromatography) applied at the final determination step gives possibility to determine individual cationic surfactants in solvent extracts of environmental samples. The LC systems coupled with mass spectrometers are most powerful tools during such analysis. Abstrakt Związki z grupy kationowych surfaktantów ze względu na swoje właściwości (bakteriobójcze, grzybobójcze, emulgujące, antykorozyjne, zmiękczające) są szeroko wykorzystywane w gospodarstwach domowych oraz przemyśle jako środki myjące, dezynfekujące i produkty farmaceutyczne. Po zastosowaniu w różnych dziedzinach działalności człowieka kationowe surfaktanty są kierowane do oczyszczalni ścieków, a następnie do wód powierzchniowych wraz z oczyszczoną wodą (ze względu na ich niecałkowitą degradacją). Ponadto, mogą one swobodnie migrować pomiędzy różnymi elementami środowiska, w tym w żywych organizmach. Zatem istotne staje się poznawanie w sposób bardziej szczegółowy zachowania, losu oraz efektów względem organizmów żywych związków z grupy kationowych surfaktantów. To zagadnienie analityczne może być rozwiązane z użycie czułych i selektywnych technik analitycznych na etapie przygotowania próbek do analizy oraz na etapie oznaczania końcowego. W ciągu ostatnich lat na etapie izolacji analitów z próbek środowiskowych wykorzystywane były głównie techniki ekstrakcji w układzie ciecz-ciecz (LLE) - ciekłe próbki lub ciało stałe-ciecz (SLE) - stałe próbki. Ta technika obejmuje zastosowanie toksycznych rozpuszczalników (chloroformu), jest czasochłonna oraz substancje przeszkadzające są współekstrahowane. Obecnie w wielu ośrodkach naukowych są prowadzone badania mające na celu zastąpienie tych tradycyjnych technik. Jak dotąd wykorzystywano następujące techniki analityczne: ekstrakcja do fazy stałej (SPE) bądź jej modyfikacja (HF-LPME) - ciekłe próbki; przyspieszona ekstrakcja za pomocą rozpuszczalnika (ASE) lub ekstrakcja za pomocą rozpuszczalnika w stanie nadkrytycznym (SFE) - stałe próbki. W celu oznaczenia sumarycznej zawartości surfaktantów w próbkach środowiskowych były najczęściej wykorzystywane tradycyjne techniki: spektrofotometrii oraz miareczkowania potencjometrycznego. Jednak stosowanie tych technik wiąże się z ich podatnością na obecność substancji przeszkadzających (anionowych i niejonowych związków). Zastosowanie na etapie oznaczania końcowego techniki chromatograficznej (chromatografii cieczowej) umożliwia oznaczanie pojedynczych kationowych środków powierzchniowo czynnych w ekstraktach rozpuszczalnikowych przygotowanych z próbek środowiskowych. Chromatografia cieczowa w połączeniu ze spektrometrią mas jest obecnie jednym z najbardziej uniwersalnych narzędzi analitycznych wykorzystywanych podczas tego typu analiz.

Surfactants in Klodnica River (Katowice, Poland). Part II. Quaternary Ammonium Compounds

Abstract The paper presents methods of determination of analytes of the cation group (alkyl benzyl dimethyl ammonium (BDDA-C12-C16), alkyl trimethyl ammonium (TMA), hexadecyl piridinium (HP)) in surface water and bottom sediment samples. In the sample preparation phase the solid phase extraction (SPE) or accelerated solvent extraction/ultrasound assisted extraction (ASE/UAE)-SPE technique was used and in the identification phase and quantitative determination of analytes phase - ion chromatography technique (combined with a conductivity detector (CD)). The determined concentrations were in the range below the determined method detection limit (MDL) or method quantification limit (MQL) figures up to 0.142 ±0.023 mg/dm3 or 2014 ±10 μg/kg (liquid and solid samples, respectively). Comparing concentrations of individual analytes found in liquid and solid environmental samples we may notice that surfactants containing a shorter alkyl chain in their molecules were found in higher concentrations in liquid samples (hydrophobicity increasing with the chain length).

Selected anionic and cationic surface active agents: case study on the Kłodnica sediments

Abstract Surface active agents (surfactants) are a group of chemical compounds, which are used as ingredients of detergents, cleaning products, cosmetics and functional products. After use, wastes containing surfactants or their degradation products are discharged to wastewater treatment plants or directly into surface waters. Due to their specific properties of SAAs, compounds are able to migrate between different environmental compartments such as soil, sediment, water or even living organisms and accumulate there. Surfactants can have a harmful effect on living organisms. They can connect with bioactive molecules and modify their function. Additionally, they have the ability to migrate into cells and cause their damage or death. For these reasons investigation of individual surfactants should be conducted. The presented research has been undertaken to obtain information about SAA contamination of sediment from the River Kłodnica catchment caused by selected anionic (linear alkylbenzene sulfonates (LAS C10-C13)) and cationic (alkylbenzyldimethylammonium (BDMA-C12-16), alkyl trimethyl ammonium (DTMA), hexadecyl piridinium chloride (HP) chlorides) surfactants. This river flows through an area of the Upper Silesia Industrial Region where various companies and other institutions (e.g. coal mining, power plants, metallurgy, hospitals) are located. To determine their concentration the following analytical tools have been applied: accelerated solvent extraction– solid phase extraction – high performance liquid chromatography – UV-Vis (anionic SAAs) and conductivity (cationic SAAs) detectors. In all sediments anionic SAAs have been detected. The concentrations of HTMA and BDMA-C16 in tested samples were higher than other cationic analytes. Generally, levels of surfactants with longer alkyl chains were higher and this observation can confirm their higher susceptibility to sorption on solid surfaces.