Lexikon

chemical analyses is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials.

Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of one or more of these components. The separation of components is generally performed prior to analysis.

Chemical analytical methods are classified according the tool they apply. According to the tools we differentiate between qualitative and quantitative analyses as well as preparatory methods.

Aim of the qualitative analysis is to find a direct or indirect proof for the presence of the substance in question or its product. Qualitative tools are: identification of the chemical compound based on physico-chemical behaviour (colour, melting point, flame-ionisation, mass-spectrum), chemical reactions, including biochemical and molecular biological (e.g. DNA) techniques, such as product of the chemical substance with a specific chemical reagent. In case of biologically active substances, the product of a biochemical reaction or the response of a biological system can also be measured. A new and very efficient analytical tool is the identification of certain DNA sequences.

Quantitative tools are based on measuring mass, volume, flux or intensity. For measuring the quantity-related endpoint the following traditional and instrumental methods can be used: gravimetry, volumetry, microscopy, spectrometry, mass spectrometry, electrochemical and thermal techniques, etc. Most of the quantitative tools apply standards to be able to express the result of the measured endpoint in concentration.

For the separation of the components of a mixture the traditional analysis applies precipitation, extraction, and distillation, the instrumental tools are the different chromatographic and electrophoretic methods.

Chemical analyses has widespread use in diagnosis and remediation, environmental science and practice, chemical industries, agriculture, food industry and all kind of other industries. The utilisation of analytical methods includes monitoring, early warning or quality assurance on the fields of human health, environment and industries.

chemical elements are a pure chemical substances consisting of one type of atom. Chemical elements are characterised by their atomic number, which is the number of protons in their nucleus. All chemical molecules consists of elements. On the http://www.chemicalelements.co website you can see the periodic table and get deatiled information by clicking on the symbol of the element.

the hazard associated with a chemical is its intrinsic ability to cause an adverse effect. It should be compared to risk, which is the chance that such effects will occur in the realty. Whilst a chemical may have hazardous properties, provided it is handled safely under contained conditions, any risk to human health or the environment is extremely low.

chemical oxidation typically involves reduction/oxidation redox reactions that chemically convert hazardous contaminants to nonhazardous or less toxic compounds that are more stable, less mobile, or inert. Redox reactions involve the transfer of electrons from one compound to another.

Specifically, one reactant is oxidized loses electrons and one is reduced gains electrons.

The oxidizing agents most commonly used for treatment of hazardous contaminants in soil are ozone, hydrogen peroxide, hypochlorites, chlorine, chlorine dioxide, potassium permanganate, and Fentons reagent hydrogen peroxide and iron.

Cyanide oxidation and dechlorination are examples of chemical treatment. This method may be applied in situ or ex situ, to soils, sludges, sediments, and other solids, and may also be applied for the in situ treatment of groundwater.

Source: US-EPA, ClU-In: http://www.clu-in.org/techfocus/default.focus/sec/In_Situ_Oxidation/cat/Overview/

a chemical process in which substances are changed into different substances. Chemical reactions are manifested by the disappearance of properties characteristic of the starting materials and the appearance of new properties that distinguish the products.

chemical Safety is achieved by undertaking all activities involving chemicals in such a way as to ensure the safety of human health and the environment.

It covers all chemicals, natural and manufactured, and the full range of exposure situations from the natural presence of chemicals in the environment to their extraction or synthesis, industrial production, transport use and disposal.

Chemical safety has many scientific and technical components. Among these are toxicology, ecotoxicology and the process of chemical risk assessment which requires a detailed knowledge of exposure and of biological effects.

Hazardous chemicals, naturally occurring or man-made, can reach our body through different routes (e.g., food, air, water) and cause a variety of health effects.

The number of existing chemicals and their compounds is very large, and for many of them the health risks are not known. Chemicals can be the result of anthropogenic sources or occur in nature. Hazardous chemicals can reach our body through different routes (e.g. food, air, water) and cause a variety of health effects.

Due to the many ways in which chemicals are used and released, the many exposure routes involved, and the different mixtures of chemicals present, the public health relevance of chemicals can be extremely difficult to assess. European Environment and Health Information System (ENHIS) indicators contribute to relate the exposure to hazardous chemicals to various policy measures that can be taken to reduce exposure or to prevent health effects.

Source: WHO — http://www.who.int/topics/chemical_safety/en/

Chemical Safety Assessment is the process aimed at determining the risk posed by a substance and, as part of the exposure assessment, develop exposure scenarios including risk management measures to control the risks. Annex I contains general provisions for performing a CSA. The CSA consists of the following steps:
- Human health hazard assessment
- Human health hazard assessment of physicochemical properties
- Environmental hazard assessment
- PBT and vPvB assessment
If, as a result of this hazard assessment, the registrant concludes that the substance meets the criteria for classification as dangerous according to Directive 67/548/EEC (for substances) or has PBT/vPvB properties, this triggers further steps in the chemical safety assessment:
- exposure assessment
- risk characterization.
(Source: REACH, Glossary)

Chemical Safety Assessment is the process aimed at determining the risk posed by a substance and, as part of the exposure assessment, develop exposure scenarios including risk management measures to control the risks. Annex I contains general provisions for performing a CSA. The CSA consists of the following steps:
- Human health hazard assessment
- Human health hazard assessment of physicochemical properties
- Environmental hazard assessment
- PBT and vPvB assessment
If, as a result of this hazard assessment, the registrant concludes that the substance meets the criteria for classification as dangerous according to Directive 67/548/EEC (for substances) or has PBT/vPvB properties, this triggers further steps in the chemical safety assessment:
- exposure assessment
- risk characterization.
(Source: REACH Glossary)

See: Chemical Safety Datasheet

The International Chemical Safety Cards (ICSCs) provide information on the intrinsic hazards of specific chemicals together with first aid and fire-fighting measures, and information about precautions for spillage, disposal, storage, packaging, labelling and transport. They are produced by the International Programme on Chemical Safety (IPCS) in collaboration with the European Commission and various national bodies.

An ICSC is designed to complement a Material Safety Data Sheet, and to be used by individual workers rather than safety specialists. The cards are produced in a standard format, which eases translation between languages. The cards are currently available in HTML or PDF format in sixteen languages, and in paper format in other languages.

(http://www.inchem.org/pages/icsc.html)

the chemical safety report documents the chemical safety assessment for a substance on its own, in a preparation or in an article or a group of substances.
In other words the Chemical Safety Report (CSR) is a document, which details the process and the results of a Chemical Safety Assessment (CSA). Annex I of the REACH Regulation contains general provisions for performing CSAs and preparing CSRs.
(Source: REACH Glossary)

the chemical safety report documents the chemical safety assessment for a substance on its own, in a preparation or in an article or a group of substances.
In other words the Chemical Safety Report (CSR) is a document, which details the process and the results of a Chemical Safety Assessment (CSA). Annex I of the REACH Regulation contains general provisions for performing CSAs and preparing CSRs. (Source: REACH Glossary)

in Annexes VII and VIII to Directive 79/831/EEC, methods for the determination of the ecotoxicity of chemical substances are enlisted. The methods are based on those recognized and recommended by competent international bodies (in particular OECD).

General introduction
1 acute toxicity for fish
2 acute toxicity for Daphnia
3 algal inhibition test
4 biodegradation: determination of the "ready" biodegradability
  4-a dissolved organic carbon (doc) die-away test
  4-b modified oecd screening test
  4-c carbon dioxide evolution test
  4-d manometric respirometry test
  4-e closed bottle test
  4-f miti test
5 degradation : biochemical oxygen demand
6 degradation: chemical oxygen demand
7 degradation: abiotic degradation: hydrolysis as a function of ph
8 toxicity for earthworms : artificial soil test
9 biodegradation: Zahn−Wellens test
10 biodegradation: activated sludge simulation test
11 biodegradation: activated sludge respiration inhibition test
12 biodegradation: modified scas test
13 bioconcentration: flow-through fish test
14 fish juvenile growth test
15 fish, short-term toxicity test on embryo and sac-fry stages
16 honeybees, acute oral toxicity test
17 honeybees, acute contact toxicity test
18 adsorption/desorption using a batch equilibrium method
19 estimation of the adsorption coefficient (koc) on soil and on sewage sludge using high performance liquid chromatography (hplc)
20 Daphnia magna reproduction test
21 soil microorganisms: nitrogen transformation test
22 soil microorganisms: carbon transformation test
23 aerobic and anaerobic transformation in soil
24 aerobic and anaerobic transformation in aquatic sediment systems

in Annexes VII and VIII to Directive 79/831/EEC, methods for the determination of the physico-chemical properties of chemical substances are enlisted. The methods are based on those recognized and recommended by competent international bodies (in particular OECD).
1 melting/freezing temperature
2 boiling temperature
3 relative density
4 vapour pressure
5 surface tension
6 water solubility
8 octanol−water partition coefficient
9 flash-point
10 flammability (solids)
11 flammability (gases)
12 flammability (contact with water)
13 pyrophoric properties of solids and liquids
14 explosive properties
15 auto-ignition temperature (liquids and gases)
16 relative self-ignition temperature for solids
17 oxidizing properties (solids)
18 number - average molecular weight and molecular weight distribution of polymers
19 low molecular weight content of polymers
20 solution / extraction behaviour of polymers in water
21 oxidising properties (liquids)

in Annexes VII and VIII to Directive 79/831/EEC, methods for the determination of the toxicity of chemical substances are enlisted. The methods are based on those recognized and recommended by competent international bodies (in particular OECD).

1 general introduction
1bis acute oral toxicity - fixed dose procedure
1tris acute oral toxicity - acute toxic class method
2 acute toxicity (inhalation)
3 acute toxicity (dermal)
4 acute toxicity: dermal irritation/corrosion
5 acute toxicity: eye irritation/corrosion
6 skin sensitisation
7 repeated dose (28 days) toxicity (oral)
8 repeated dose (28 days) toxicity (inhalation)
9 repeated dose (28 days) toxicity (dermal)
10 mutagenicity − in vitro mammalian chromosome aberration test)
11 mutagenicity − in vivo mammalian bone-marrow chromosome aberration test
12 mutagenicity mammalian erythrocyte micronucleus test
13/14 mutagenicity − reverse mutation test using bacteria
15 gene mutation − Saccharomyces cerevisae
16 mitotic recombination − Saccharomyces cerevisae
17 mutagenicity − in vitro mammalian cell gene mutation test
18 dna damage and repair − unscheduled dna synthesis − mammalian cells in vitro
19 sister chromatid exchange assay in vitro
20 sex-linked recessive lethal test in Drosophila melanogaster
21 in vitro mammalian cell transformation test
22 rodent dominant lethal test
23 mammalian spermatogonial chromosome aberration test
24 mouse spot test
25 mouse heritable translocation
26 sub-chronic oral toxicity test. Repeated dose 90-day toxicity study in rodents
27 sub-chronic oral toxicity test: repeated dose 90-day toxicity study in non-rodents
28 sub-chronic dermal toxicity test: 90-day repeated dermal dose study using rodent species
29 sub-chronic inhalation toxicity test: 90-day repeated inhalation dose study using rodent species
30 chronic toxicity test
31 teratogenicity test rodent and non-rodent
32 carcinogenicity test
33 combined chronic toxicity/carcinogenicity test
34 one-generation reproduction toxicity test
35 two generation reproduction toxicity test
36 toxicokinetics
37 delayed neurotoxicity of organophosphorus substances following acute exposure
38 delayed neurotoxicity of organophosphorus substances 28 day repeated dose study
39 unscheduled dna synthesis (uds) test with mammalian liver cells in vivo
40 skin corrosion (in vitro)
41 phototoxicity − in vitro 3t3 nru phototoxicity test
42 skin sensitisation: local lymph node assay
43 neurotoxicity study in rodents

chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic.

These chemical processes need water, and occur more rapidly at higher temperature, so warm, damp climates are best.It means that soil formation is faster under tropic klimate compared to moderate or cold climate.

Chemical weathering (especially hydrolysis and oxidation) is the first stage in the production of soils.
There are different types of chemical weathering, the most important are:

Solution - removal of rock in solution by acidic rainwater. In particular, limestone is weathered by rainwater containing dissolved CO₂, (this process is sometimes called carbonation).

Hydrolysis - the breakdown of rock by acidic water to produce clay and soluble salts.

Oxidation - the breakdown of rock by oxygen and water, often giving iron-rich rocks a rusty-coloured weathered surface.

the management of chemical substances and products during their whole life time, from design up to and including disposal at the end of their life, in such a way that all optimal balance is obtained between acceptable risk and maximum benefit for society in the short, medium and long-term.

a collective term for chlorinated derivatives of benzene, toluene, phenol, naphthalene and bi-phenyl and other compounds containing at least one benzene ring. Chlorinated aromatics are widely used as intermediates in the manufacture of medicines, agricultural chemicals and paints.

chlorinated paraffins are chemicals manufactured by chlorination of liquid n-paraffin or paraffin wax. The largest application for chlorinated paraffins is as a plasticiser and flame retardant in flexible PVC. They are also used as plasticisers in paint, sealants and adhesives. Higher chlorine content grades are used as flame retardants in a wide range of rubbers and polymer systems. Another major outlet for chlorinated paraffins is in the formulation of metalworking lubricants where they have long been recognised as one of the most effective additives for lubricants used in a wide range of machining and engineering operations. Finally, they are used in leather formulations.

chlorinated solvents are chloride containing organic liquids which have the power to dissolve organic substances and materials.Trichloroethylene, tetrachloroethylene (also known as perchloroethylene), and methylene chloride are the main solvents in this group. Due to their non-flammability, these compounds have been widely used for cleaning metals in the electronics industry and for dry cleaning of clothes. The use of 1,1,1-trichloroethane was phased out at the end of 1995 under the Montreal Protocol.

chlorine is a greenish yellow gas on normal temperature and pressure. At -34°C it turns to a liquid. It is the eleventh most common element in the earth's crust and is widespread in nature. Chlorine is a key building block of modern chemistry and used in three principal ways: direct use (e.g. to disinfect water); as a raw material for chlorine-containing products (e.g. plastics, pharmaceuticals, pesticides) and as an intermediate to manufacture non-chlorinated products.

chlorobenzenes are a group of cyclic aromatic compounds in which one or more hydrogen atoms of the benzene ring have been replaced by a chlorine atom. The generic molecular formula is C₆H_6–nCl_n, where n = 1–6. There are 12 different chlorinated benzenes: monochlorobenzene (MCB), dichlorobenzene (DCB) (three isomers), trichlorobenzene (TCB) (three isomers), tetrachlorobenzene (TeCB) (three isomers), pentachlorobenzene (PeCB), and hexachlorobenzene. MCB, 1,2-DCB, 1,3-DCB, and 1,2,4-TCB are colourless liquids, while all other congeners are white crystalline solids at room temperature. The solubility of chlorobenzenes in water is low (decreasing with increasing chlorination), flammability is low, the octanol/water partition coefficients are moderate to high (increasing with increasing chlorination), and vapour pressures are low to moderate (decreasing with increasing chlorination).
They are used mainly as intermediates in the synthesis of pesticides and other chemicals; 1,4-dichlorobenzene is used in space deodorants and as a moth repellent. The higher chlorinated benzenes have been used as components of dielectric fluids.
Clorobenzenes other than hexachlorobenzene have low or moderate toxicity to human, and the risk of chlorinated benzenes causing harm to aquatic and terrestrial organisms is considered to be low too.
Their physicochemical properties suggest that chlorobenzenes released to the environment are likely to be volatilized to the atmosphere. The Henry’s law constants measured for chlorobenzenes suggest that they are readily volatilized, especially from aquatic systems with long residence times, such as large lakes and oceans. However, chlorobenzenes released to water may also be adsorbed onto sediment, especially if it is rich in organic matter. Volatilization from soil is also likely, although, depending on the characteristics of the soil, there may also be sorption to soil. The most important factor affecting the behaviour and fate of chlorobenzenes in soil is sorption. adsorption–desorption processes in soil affect the rate of volatilization and leaching and the availability of chemicals to microbial and chemical degradation or uptake by plants or other organisms. The soil sorption coefficients for chlorobenzenes range from 466 to 58 700 and generally increase with increasing chlorination. sorption of chlorobenzenes to soil is affected by many parameters, and it increases with increasing organic matter content.
chlorobenzenes in soil, sediment, and sewage sludge can be degraded by microorganisms. The major mechanism of aerobic degradation is via oxidative dechlorination, usually initiated by dioxygenative hydroxylation, leading to the formation of hydroxylated aromatic compounds (mainly catechols), which undergo ring fission and subsequent mineralization to carbon dioxide and water. The less chlorinated benzenes are more readily degraded than the higher chlorinated ones. biodegradation under anerobic conditions has also been reported, although this occurs at a slower rate than aerobic biodegradation.
They are accumulated by water and terrestrial organisms, mainly in the fat tissue or in the liver of higher organisms.

chloroform is produced by the chlorination of methane (CHCl₃), and is used as an intermediate in the production of refrigerants, agrochemicals and fluoropolymers. It is no longer used as an anaesthetic.

chlorophenols are derivatives of phenols that contain one or morecovalenly bonded chlorine atoms. Most chlorophenols have a number of different isomer. Monochlorophenols have three isomers because there is only chlorine atom which can occupy one of three ring positions on the phenol molecule; dichlorophenols have 4, trichlorophenols: 6, tetrachlorophenols: 3, and pentachlorophenols only one.
In the past, it has been used as a herbicide, insecticide, fungicide, algaecide, disinfectant and as an ingredient in antifouling paint. Some applications were in agricultural seeds (for nonfood uses), leather, masonry, wood preservation, cooling tower water, rope and paper mill system.
Since the early 1980s, the purchase and use of PCP in the U.S has not been available to the general public. Nowadays most of the PCP is restricted to the treatment of utility poles and railroad ties.

structural chromosome damage expressed as breakage of single chromatids or breakage and reunion between chromatids.

the resultant electrical output of sample components passing through a detection system following chromatographic separation. A chromatogram may also be called a trace. The chromatogram gives qualitative and quantitative information on the sample.

representation of the composition of a substance from the characteristic distribution of constituents in an analytical chromatogram.

chromatography is a separation method based on the difference in interactions between the components of the sample dissolved in a fluid phase (gas or liquid) and the stationary phase. The driving force of the transport between the phases is the difference in chemical potential. The retention in the stationary phase (partition) depends on the interactions of the molecules, ions, atoms of the sample. As a consequence, their average velocity will be different, and they leave the stationary phase separated. The separated components are detected based on their physical or chemical properties. The stationary phase can be solid or liquid. The mobil phase can be gas, supercritical fluid or liquid. Depending on the mobil phase the chromatographic techniques are classified as gas chromatography, supercritical fluid chromatography and liquid chromatography. (Source: Balla J.: Analytical applications of gas chromatography. Budapest, 1987) All of these chromatographic techniques are widely used for characterization of various mixtures, e.g. environmental samples in site assessment, technology monitoring, etc.

structural chromosome damage expressed as breakage, or breakage and reunion, of both chromatids at an identical site.

Concise International Chemical Assessment Documents (CICAD). Concise documents that provide summaries of the relevant scientific information concerning the potential effects of chemical substances on human health and the environment; published by the IPCS (WHO International Programme on Chemical Safety).

circulating wells (CWs) provide a technique for subsurface remediation by creating a three-dimensional circulation pattern of the ground water. Ground Water is drawn into a well through one screened section and is pumped through the well to a second screened section where it is reintroduced to the aquifer. The flow direction through the well can be specified as either upward or downward to accommodate site-specific conditions. Because ground water is not pumped above ground, pumping costs and permitting issues are reduced and eliminated, respectively. Also, the problems associated with storage and discharge are removed. In addition to ground water treatment, CW systems can provide simultaneous vadose zone treatment in the form of bioventing or soil vapor extraction.

CW systems can provide treatment inside the well, in the aquifer, or a combination of both. For effective in-well treatment, the contaminants must be adequately soluble and mobile so they can be transported by the circulating ground water. Because CW systems provide a wide range of treatment options, they provide some degree of flexibility to a remediation effort.

Source: US-EPA, Clu-In: http://www.clu-in.org/techfocus/default.focus/sec/Ground-Water_Circulating_Wells/cat/Overview/

the cytoplasm is the part of a cell that is enclosed within the cell membrane. In eukaryotic cells, the contents of the cell nucleus are not part of the cytoplasm and are instead called the nucleoplasm. In eukaryotic cells, the cytoplasm contains organelles, such as mitochondria, Golgi, lysosomes and spherosomes. The cell organelles are filled with liquid that is kept separate from the rest of the cytoplasm by biological membranes. The cytoplasm is the site where most cellular activities occur, such as many metabolic pathways like glycolysis, and processes such as cell division. The inner, granular mass is called the endoplasm and the outer, clear and glassy layer is called the cell cortex or the ectoplasm.

The part of the cytoplasm that is not held within organelles is called the cytosol. The cytosol is a complex mixture of cytoskeleton filaments, dissolved molecules, and water that fills much of the volume of a cell. The cytosol is a gel, with a network of fibers dispersed through water. Due to this network of pores and high concentrations of dissolved macromolecules, such as proteins, an effect called macromolecular crowding occurs and the cytosol does not act as an ideal solution. This crowding effect alters how the components of the cytosol interact with each other.

(Crowding occurs since these high concentrations of macromolecules reduce the volume of solvent available for other molecules in the solution, which has the result of increasing their effective concentrations. This crowding effect can make molecules in cells behave in radically different ways than in test-tube assays. Consequently, measurements of the properties of enzymes or processes in metabolism that are made in the laboratory in dilute solutions may be different by many orders of magnitude from the true values seen in living cells. The study of biochemical processes under realistically crowded conditions is very important, since these conditions are a ubiquitous property of all cells and crowding may be essential for the efficient operation of metabolism.)

Source: Wikipedia

An Analysis of National and EU RTD Programmes related to Sustainable Land and Groundwater Management
Proceedings of the Conference on "Sustainable Management of Contaminated Land"
Variation in calculated human exposure. Comparison of calculations with seven European human exposure models
Special Edition on Land Contamination and Reclamation: The Sustainable Management and remediation of Contaminated Land

classification and labelling includes the evaluation of the hazard of a substance or preparation in accordance with Directive 67/548/EEC (substances) and 1999/45/EC (preparations) and a communication of that hazard via the label.
Classification is the process in which a given substance or preparation is assigned one of the 15 categories of danger depending on their intrinsic properties in accordance with the criteria for specified in directive 67/548/EEC. If the substance is not found to be dangerous, according to the said criteria, then it is not classified. Under GHS the substance or preparation will be assigned to hazard classes.
This evaluation must be made for any substance or preparation manufactured, imported or placed on the EU market for any tonnage level.
The classification of the substance and preparations as being dangerous is based on one or several endpoints concerning physical-chemical properties, health or environmental effects.

• explosive substances and preparations
• oxidising substances and preparations
• extremely flammable substances and preparations
• highly flammable substances and preparations
• flammable substances and preparations
• very toxic substances and preparations
• toxic substances and preparations
• harmful substances and preparations
• corrosive substances and preparations
• irritant substances and preparations
• sensitising substances and preparations
• carcinogenic substances and preparations
• mutagenic substances and preparations
• substances and preparations which are toxic for reproduction
• substances and preparations which are dangerous for the environment

Under REACH, any manufacturer or importer of a substance (regardless of quantity) will be required to submit all its classifications to the Agency, to be included in the classification and labelling Inventory. Classifications must be submitted by 1 December 2010 if the substance is put on the market and is either classified as dangerous (no tonnage threshold) or subject to registration.
The classification has to be included in all registration dossiers.
Classifications should also be communicated in the notifications which are required for substances for research and development (PPORD) and substances in articles.
The classification and labelling inventory is a database maintained by the European Chemical Agency (ECHA) containing the classification of all substances submitted either in registration dossiers or in notification of classification and labelling, including in PPORD notifications. Information from this inventory, which includes substance name and classification and labelling is made publicly available in accordance with the provisions of Article 119 of the REACH Regulation.

Source: REACH Glossary, http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:1999:200:0001:0068:EN:PDF