Chemical and microbiological analysis

Using the utmost precision and reliability, we undertake physical-chemical and microbiological testing for our customers in accordance with legal regulations such as the German Drinking Water Ordinance or the Water Framework Directive. In addition, we offer the quantitative determination of inorganic and organic micropollutants using modern and high-performance methods of analysis and instruments in the most diverse matrices (drinking water, groundwater, surface water, waste water, sewage sludge, soil, suspended matter and sediments). A key focus is on the continuous development and improvement of methods of trace analysis for both water and solid samples. We are accredited according to DIN EN ISO 17025 for the testing of drinking water, untreated water, groundwater and surface water.

Microbiological detection methods range from the specific detection of indicator organisms or pathogens to the enrichment of large volumes of water to improve the sensitivity of the detection methods to the analysis of microbial substances such as AOC (assimilable organic carbon). Additionally, we use the latest molecular biological methods to quickly identify the species or microorganisms and to determine antibiotic resistance genes.

We have methods of analysis for representatives of the following substance groups:

• Trace elements and metals
• Bromide, bromate, chlorite, chlorate, iodide, iodate and perchlorate
• Speciation of arsenic, chromium and selenium
• Pesticides and metabolites (more than 100 single substances including glyphosate, AMPA, N,N-dimethyl sulphamide, desphenyl chloridazon, other PSM metabolites)
• Aromatic sulfonates
• Chelating agents
• Pharmaceutical residues (more than 100 single substances)
• Iodinated X-ray contrast agent/s
• Endocrine-disrupting chemicals (steroidal hormones, alkyl phenols)
• Per and polyfluoroalkyl substances (PFAS)
• Aliphatic amines
• Nitrosamines
• Biocides
• Benzotriazoles
• Artificial sweeteners
• Chlorinated and brominated flame retardants
• Organophosphonic acids
• Nitrification inhibitors
• Surrogate parameters (DOC, TOC, AOX, AOS, AOF, EOF, TOP-assay)

We offer the following range of microbiological detection methods:

• Detection of indicator bacteria according to the German Drinking Water Ordinance: E. coli / coliform bacteria, Enterococci, Clostridium perfringens, colony counts 22 °C, 36 °C
• Detection of pathogens: Pseudomonas aeruginosa, Legionella, aeromonads, thermotolerant Campylobacter spp., testing for Cryptosporidium and Giardia lamblia, testing for antibiotic-resistant bacteria, detection of multiresistances using agar diffusion tests
• Detection of bacteriophages: F-specific RNA bacteriophages, somatic coliphages
• Enrichment methods: To rapidly enrich large volumes of water, TZW has developed practical enrichment methods that enable us to concentrate water volumes of 100 litres and more. Using this methodology, the detection sensitivity for subsequent microbiological analysis (e.g. for the indicator organisms E. coli, coliform bacteria and enterococci) can be increased by a factor of 1000. This enables distribution networks to be investigated systematically for possible contamination sources of microbiological pollutants.
• Assimilable organic carbon (AOC) / regrowth potential: Regrowth potential, determination of AOC increase by means of chlorination, determination of AOC following various treatment stages
• Special methods to evaluate the microbiological water quality: Determination of the total cell count (microscopic, flow cytometry), microscopic analysis of floating layers, sediments, coatings, plant cover and biofilms, problem-oriented investigations into specific bacteria groups (e.g. iron and manganese oxidisers, Crenothrix polyspora), biomass determination (e.g. ATP, protein), microbial count (colony counts and Most-Probable-Number (MPN) method): Colony counts for various media, nitrate/iron(III)/sulphate-reducing bacteria, pollutant-degrading bacteria
• Animal organisms (invertebrates): Advice on the presence of animal organisms in water supply systems, identification and quantification of animal organisms