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Preventative action for health

A dense network of laws and directives provides information on environmental factors relating to when and in what quantities they can be tolerated and when they start to become a risk to human health. Comprehensive and precise analyses are required to conform with threshold values. Testing laboratories such as the Stuttgart-based UIS Umweltinstitut synlab GmbH carry out such analyses.

The best medicine is prevention – comprehensive national and international regulations exist which provide information on the threshold values of environmental factors with a potential risk for human health. The environmental factors in question originate from a broad range of sources, including water, soil, air and food; they can be natural or artificial. In order to guarantee a consistent monitoring of threshold values, testing schemes and intervals have been defined to lay out which analyses have to be carried out when. Such work often requires time-consuming procedures as well as precise and expensive equipment, which is where specialised companies come in.

This high-tech device combines two mass spectrometers in a row. The gas chromatograph is mainly used for the analyses of samples for the presence of pesticides. © UIS Umweltinstitut synlab GmbH

UIS Umweltinstitut synlab GmbH is one such company with its own testing laboratory. The company is an amalgam of three independent environmental institutes, two of which were founded back in the 1970s, and which joined forces in 2004 to pool their competences with the establishment of a new "GmbH" (limited liability company). The company now has subsidiaries in south and east Germany, Austria and Hungary. The Stuttgart-based central laboratory specialises in food and water analyses and also deals with special analyses. The teams carry out the entire range of related activities from sampling to sample logistics and tests.

Analysis devices are the most important pieces of equipment used by the staff of 45 in the Stuttgart laboratories. These devices, which are based on the chemical principle of adsorption and desorption, are equipped with separation columns for chromatographic investigations. "Although we buy in the devices, we ourselves develop analysis methods that are tailored to specific requirements. Sometimes we also use the manufacturers' applications," said Robert Ottenberger, head of the Stuttgart subsidiary. Depending on the analyte under investigation, the team uses either gas- or liquid chromatographs. Thermally stable substances are usually analysed with gas chromatographs. Depending on the substance to be tested - mineral water or industrial wastewater - there are any number of a broad range of different methods available.

Water-related investigations

However, there are some general trends: “Nowadays, we like to use very small columns along with much smaller quantities of sample and solvent. This reduces our waste, which also helps us to reduce costs,” said Ottenberger. The term “small column” is relative, considering that “small” columns can be up to 50 metres long. However they are very thin. “Such columns are thinner than wire and are wrapped like wire. This enables us to analyse samples down to the ppt range,” said Ottenberger. The company’s major clients in the water analysis sector are mainly producers of medicinal and mineral water, as well as communal waste management authorities and water supply companies. “We investigate all parameters stipulated in drinking and mineral water regulations. Around 80 per cent of the companies that operate mineral water fountains in southern Germany contract our services. In this sector it is standard practice to have the water analysed by several testing laboratories,” added Ottenberger. Companies such as UIS therefore make a huge contribution to making drinking and mineral water in Germany one of the best examined and safest foodstuffs.

The UIS analyses the concentration of mineral substances as well as water samples for the presence of pesticides and applies special methods in the case of problematic environmental factors such as uranium. Prior to analysis, the water samples are concentrated (up to 500- to 2000-fold), explains Ottenberger. Columns are not suitable for testing the samples for their bacterial load. Instead, the testing laboratories enrich the bacteria using nutrient media and membrane filters. In addition, the researchers look for indicator parameters. For example, E. coli is an indicator that drinking water is polluted with faeces.

Plant product-related investigations

This device is used to analyse soil, water and air samples for the presence of volatile contaminants. The vials in the sampler are analysed automatically overnight. © UIS Umweltinstitut synlab GmbH

Another important business area established by UIS over the last few years is the analysis of food of plant origin. Fruit and vegetables, coffee and spices are analysed for the presence of harmful substances such as pesticides, heavy metals and mycotoxins. Here, the devil is in the details and the work starts with the preparation of the samples. The samples are ground and pureed and a broad range of solvents are added. Strawberries are quite different from coconut shells and the plant tissues of these two fruits are as different as the methods used to prepare the samples. In order to ensure that all substances are dissolved from the matrix, the researchers carry out recovery determinations: The laboratory staff prepares a contaminated sample of precisely defined composition and concentration. This sample is then used as a reference for the sample under investigation. UIS mainly analyses the final plant products, i.e. the fruit and vegetables prior to sale. Sometimes the scientists also carry out analyses before the fruit and vegetables are harvested. Some bio-associations are very strict. They not only require the laboratories to test compliance with the legally allowed maximum amounts, but to completely exclude the presence of diverse substances such as pesticides. Conventional agriculture has to comply with regulations stipulating which pesticides can be used in which quantities and combinations in which growth phases. The gap-free examination of all growth phases is neither practical nor affordable. However, the analysis of the final plant products provides information on how the plants were treated previously. However, if, for example, a pesticide was applied so early and in such small amounts that it is completely degraded when the fruit are harvested, it is impossible to detect that the sought-after pesticide was actually applied. Does this then mean that the analyses are no longer relevant? This is not a question for the analysts themselves to answer, but more an issue for ideological debate.

Who controls the controllers?

In the field of analysis, everything must underlie quality management processes. The UIS works with numerous public and sworn experts as well as evaluators with special knowledge. The investigation methods are accredited according to German and European standards. Accreditation is not an easy matter in the food sector: Even though European-wide accreditation exists, each analysis still has to be approved on a federal and state level, as each German state tends to have different regulations. This might result in the fact that testing institutes can carry out a certain analysis in Lower Saxony but not in Bavaria, where special regulations have been put in place that require the process to be modified.

UIS has voluntarily opted for certification according to the QS system guidelines for fruit, vegetable and potato analysis. This system guarantees the systematic monitoring of all the partners along the supply chain. The objective of the system is to guarantee work in compliance with the German “Residue and Maximum Amount Regulation” (maximum amounts of pesticides, for example) and the exclusive use of approved substances. All companies accredited according to the QS system, including UIS, receive doted samples twice a year as part of a round robin test, which they have to analyse without faults.

UIS Umweltinstitut synlab GmbH
Robert Ottenberger
Hohnerstraße 23
70469 Stuttgart
Tel.: +49 (0)711 16272-0
Fax: +49 (0)711 16272-51
E-mail: robert.ottenberger(at)synlab.de

Website address: https://www.gesundheitsindustrie-bw.de/en/article/news/preventative-action-for-health