Advanced analytical methods in the determination of xenobiotics in water samples

Transcription

1 Advanced analytical methods in the determination of xenobiotics in water samples Joonas Nurmi Department of Ecological and Environmental Sciences Faculty of Biosciences

2 Outline of presentation Background Chemicalisation Xenobiotics in water Objective and methods Chromatography Time-of-flight mass spectrometry Accurate mass measurements Previous research Non-target water analysis Joonas Nurmi

3 1. Background - Chemicalisation - Xenobiotics Faculty of Biosciences

4 Chemicalisation Definition: Chemicalisation signifies the increasing use of chemicals and environmental pollution happening in consequence of that. Pollution caused by the use of chemicals can also be unintentional or unconscious! Joonas Nurmi

5 How many chemicals? Exact number is impossible to give Chemical Abstracts Service (CAS) organic and inorganic substances with CAS Registry Number commercially available chemicals inventoried / regulated substances Finnish Environment Institute (SYKE) :06 Over products which contain hazardous compounds are imported or produced in Finland Number of compounds in these products is over Joonas Nurmi

6 What s the problem? Chemicals may have impacts on nature, urban environment, working environment or households depending on the properties of chemicals and how they are used. Generally - concentrations of organic compounds in environment are poorly known Information is limited to few compounds New chemicals are produced all the time Emerging contaminants? Lack of research causes delay in legislation Joonas Nurmi

7 Small history of chemicalisation 1/2 Ancient chemistry 7000 B.C. Middle East: alkali, limestone glass production 900 A.D. China: black powder gun powder Industrial revolution Inorganic chemistry GB: mass production of soda ash soap, glass s synthetic dyes textile industry Organic chemistry, Europe, late 19 th century synthetic fertilizers crop yield improvement s chemicals for oil petrochemical products II World War short industrial break Joonas Nurmi

8 Small history of chemicalisation 2/ increased use of pesticides, organohalides, pharmaceuticals, industrial chemicals 1962 Rachel Carson: Silent spring Start of environmental movement Dichloro diphenyl trichloroethane, DDT organochlorine insecticide probable human carcinogen, damages the liver nervous system, reduces reproductive success, damages reproductive system Cl Banned in Finland since1976 Cl Cl 2001 Stockholm Convention Cl Cl Joonas Nurmi

9 EPA s dirty dozen Aldrin ¹ Chlordane ¹ Dichlorodiphenyl trichloroethane (DDT) ¹ Dieldrin ¹ Endrin ¹ Heptachlor ¹ Hexachlorobenzene ¹,² Mirex ¹ Toxaphene ¹ Polychlorinated biphenyls (PCBs) ¹,² Polychlorinated dibenzo-p-dioxins ²(dioxins) Polychlorinated dibenzofurans ² (furans) Endrin 1-Intentionally produced. 2-Unintentionally produced - Result from some industrial processes and combustion. Joonas Nurmi

10 Classification of chemicals: 1. Basic chemicals Polymers Mainly packing materials - e.g. polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), polypropylene (PP) Petrochemicals Made from liquefied petroleum gas, natural gas, and crude oil - e.g. benzene, toluene, xylenes, methanol Industrial chemicals - e.g. synthetic rubber, surfactants, dyes and pigments, turpentine, resins, carbon black, explosives and rubber products Joonas Nurmi

11 Classification of chemicals: 1. Basic chemicals Inorganic chemicals Oldest chemical category - e.g. salt, chlorine, caustic soda, soda ash, acids (such as nitric, phosphoric, and sulfuric), titanium dioxide, and hydrogen peroxide Fertilizers e.g. phosphates, ammonia, and potash chemicals Joonas Nurmi

12 Classification of chemicals: 2. Life sciences While much smaller in volume than other chemical sectors, their products tend to have very high prices Product groups: Pharmaceuticals Animal health products Vitamins Crop protection chemicals - herbicides, insecticides, and fungicides Joonas Nurmi

13 Classification of chemicals: 3. Specialty chemicals Category of relatively high valued, rapidly growing chemicals with diverse end product markets Generally characterized by their innovative aspects Sold for what they can do rather than for what chemicals they contain Product groups: electronic chemicals, industrial gases, adhesives and sealants as well as coatings, industrial and institutional cleaning chemicals and catalysts Joonas Nurmi

14 Classification of chemicals: 4. Consumer products Most of chemicals are used in manufacture of other items, although a smaller number are used directly by consumers Major industrial customers include rubber and plastic products, textiles, apparel, petroleum refining, pulp and paper, and primary metals Consumer products: soaps cosmetics detergents Joonas Nurmi

15 Breakdown of the chemicals in commerce in USA Estimated number and categories of chemicals in commerce registered in the USA over the past 30 years Industrial Food additives Cosmetics ingredients Pharmaceuticals Pesticides Derek et al. Environ. Sci. Technol. (2006) 40:7157. Joonas Nurmi

16 Xenobiotics - definitions A xenobiotic is a chemical which is found in an organism but which is not normally produced or expected to be present in it. It can also cover substances which are present in much higher concentrations than are usual Xenobiotics is very often used in the context of pollutants such as dioxins and polychlorinated biphenyls and their effect on the biota, because xenobiotics are understood as substances foreign to an entire biological system Joonas Nurmi

17 Potential emerging pollutants Phosphorus flame retardants (PFR) O Brominated flame retardants (BFR) HO (CF 2 ) 8 CF 3 Polyfluorinated organic compounds (PFC) Short chain chlorinated paraffins (CP) O O P O O Cl Cl Br Cl Cl Cl Cl HO Br Br Br OH Joonas Nurmi

18 2. Objectives and methods - Chromatography - Mass spectometry Faculty of Biosciences

19 Objectives of the study Identification of emerging organic pollutants by non-target screening of waste waters Development of novel qualitative and quantitative instrumental techniques to analyze organic xenobiotics in different water samples E.g. surface water, storm water, waste water Assessment of environmental effects of organics in water system by ecotoxicological research methods Joonas Nurmi

20 Chromatography Collective name of laboratory separation techniques Separation is based on the interaction of a compound between two phases: mobile phase and stationary phase Gas chromatography (GC): - Mobile phase: gas, Stationary phase: liquid - Carried out in a column Liquid chromatography (LC): - Mobile phase: liquid, Stationary phase: solid - Carried out either in a column or a plane Joonas Nurmi

21 Mass spectrometry Mass spectrometry (MS) is an analytical technique for the determination of the elemental composition of a sample or molecule Sample is loaded onto ion source which splits the sample molecules into ions Mass analyzer sorts the ions by their masses by applying electromagnetic fields Detector measures the value of an indicator quantity and thus provides data for calculating the abundances of each ion present Joonas Nurmi

22 Time-of-flight mass spectrometry (TOF-MS) The time-of-flight (TOF) analyzer uses an electric field to accelerate the ions through the same potential, and then measures the time they take to reach the detector. If the particles all have the same charge, the kinetic energies will be identical, and their velocities will depend only on their masses. Lighter ions will reach the detector first. Joonas Nurmi

23 Resolution key to accurate mass Resolution R can be defined as the ability to separate and measure the masses of ions of similar, but not identical, molecular mass. High resolution > 5000 Joonas Nurmi

24 3. Previous research - Non-target analysis Faculty of Biosciences

25 Screening methods Pre-target screening: analytes are pre-selected before MS-data acquisition, other positives cannot be revealed Post-target screening: all compounds eluted from column are measured by MS and the m/z of target analytes are extracted afterwards Non-target screening: compounds eluted from column can be measured and identified without any kind of selection search of unknown compounds, no previous information about the analytes is taken into account Joonas Nurmi

26 Outline of non-target analysis 1. Sampling 2. Sample pretreatment 3. Separation of compounds, e.g. GC / LC good separation efficiency 4. Detection of compounds, e.g. TOF-MS accurate mass measurement 5. Data analysis component deconvolution with proper software elemental composition of components library search of components 6. Validation of results use of standard compounds Joonas Nurmi

27 Ionization in mass spectrometry Cl O Electrospray ionization positive polarity [M+H] + Cl N N Protonated molecule Imazalil C 14 H 14 N 2 OCl 2 Protonated Imazalil C 14 H 15 N 2 OCl 2 Exact mass: C 14 H 14 N 2 O 35 Cl 2 : 296,0482 C 14 H 14 N 2 O 35 Cl 37 Cl: 298,0453 Exact mass: C 14 H 15 N 2 O 35 Cl 2 : 297,0561 C 14 H 15 N 2 O 35 Cl 37 Cl: 299,0532 Joonas Nurmi

28 Conclusions Increased numbers of chemicals are produced and used all the time. More information about the concentrations of organic compounds in water system is needed to assess impacts of chemicals on the environment. Chemical diversity of xenobiotics requires the use various analytical techniques. Chromatography combined with high resolution mass spectrometry enables the analysis of complex mixtures and identification of unknown compounds. Joonas Nurmi