Residue Analysis

What are pesticides, herbicides and fungicides?

Pesticide residues are residues of crop protection products that can be detected in food after the crops have been harvested. Polar pesticides are widely used in agriculture in the form of herbicides, growth regulators, ripening accelerators or fungicides.

Herbicides and fungicides are two subsets of pesticides. Herbicides kill unwanted plants and weeds, while fungicides prevent fungal growth near crops. Biocides, on the other hand, also control harmful organisms and are commonly used in medicine and in agriculture and forestry. Examples of biocides include rat poison, wood preservatives and repellents.

Regulation (EU) 396/2005 sets maximum residue levels of pesticides for plant- and animal-based products.

Tentamus operates a worldwide network of laboratories, equipped with state-of-the-art instrumentation, specialized in residue analysis. These laboratories are accredited to perform analyses on food and food supplements.

1. Residue analysis of crop protection products

Residue analysis for pesticides and other crop protection products is performed by LC and GC (plus various detection modules). This method includes:

• Fruit monitoring, monitoring of vegetables and their processed products such as jam, canned fruits, frozen vegetables.
• Analysis of polar pesticides (e.g. glyphosate, phosphonic acid, ethephon, TMS, chlormequat, chlorate, perchlorate, etc.)

2. Residue analysis of food of plant origin

• Includes contaminants from fertilizers and crop protection products (e.g. phosphorus, nitrogen, potassium)
• Fruitmonitoring: analysis of fresh fruits, vegetables and their processed products for nitrate (by HPLC)

Ammonium nitrate is a nitrate-based fertilizer commonly used on soils. Safe use and storage of nitrate fertilizers is critical to protecting livestock. The use of nitrate fertilizers is limited because excessive residues in crops are considered contaminants and can have negative health effects if consumed in large amounts.

3. Residue analysis of food of animal origin.

Animal foods such as milk and meat may contain residues of pharmaceuticals (e.g., antibiotics) originally used to prevent or treat diseases in animals.

High levels of antibiotics in animal products contribute to the development of antibiotic resistance, and human use of antibiotics is no longer effective in treating illness. To avoid these immunities, it is important to limit the amount of antibiotics used in animal feed.

Other analyses include:

• Isotope analyses and LC-IRMS for testing antibiotics in honey and for medication of bees.
• LC-MS/MS screening to test for residues of veterinary drugs in food samples.

Prohibited substances or increased levels of chemical substances in cosmetics can quickly lead to recalls and loss of image and thus become an expensive undertaking for the cosmetics manufacturer. Accordingly, cosmetics must also be subjected to regular residue analyses.

The following substances and chemical compounds are within the scope of services of the accredited Tentamus laboratories and can be routinely analyzed for you in accordance with the Cosmetics Regulation:

1. Residue analysis of crop protection products in cosmetics

Residues of crop protection products are normally more expected in food. However, this analysis also plays an important role in cosmetic products – especially in natural cosmetics.

Crop protection products can enter the product via contaminated plant raw materials. These may only be present in quantities that are harmless to health and technically unavoidable.

The Tentamus laboratories analyze pesticide residues in cosmetics by LC-GC with a spectrum of more than 600 individual substances.

2. Residue analysis of chemical residues in cosmetics

Elevated levels of formaldehyde and nickel, unlisted dyes or even banned preservatives in cosmetic products quickly lead to product recalls. If cosmetics contain these substances or too much of them, they are considered unfit for sale. The laboratories of the Tentamus Group carry out analyses by LC-GC to check the residues and limit values mentioned and, if necessary, to identify banned substances.

3. Residue analyses for further substances in cosmetics

• Care substances (glycerin, panthenol, tocopherol, allantoin, bisabolol, hyaluronic acid)
• Declarable fragrances incl. Majantol
• Dioxane, ethylene oxide
• Fluoride
• Fragrances
• Heavy metals incl. determination chromium (VI) & sweat soluble nickel
• Nitromusks & polycyclic musk compounds
• Nitrosamines incl. NDELA
• Organohalogen compounds
• Plasticizers (phthalates)
• Preservatives
• Polycyclic aromatic hydrocarbons (PAHs)
• Quaternary ammonium compounds
• Solvent residues (e.g. benzene & toluene)
• Surfactants

1. Residue analysis of pesticide residues in pharmaceuticals

Residue analysis of pharmaceutical products is usually already focused on the starting raw material. Thus, pesticide residues may already enter the raw material before production.

Using highly sensitive HPLC and GC equipment, pesticide residues can be determined and compared with an extensive database in our laboratories.

2. Residue analysis of chemical substances in pharmaceuticals

Chemical substances can also be introduced into pharmaceutical products during the production process. Residues of solvents, sulfated ash or ethylene oxide and dioxane are analyzed by gas chromatography (GC-MS).

Tentamus führt seine analytischen Tests nach den einschlägigen Vorschriften durch und verwendet diese als Richtlinie für die Einhaltung der gesetzlichen Grenzwerte.

Methods used for residue analysis in the Tentamus Group include:

• HPLC: High Performance Liquid Chromatography is a method that separates, identifies and quantifies each component that makes up a mixture.
• LC-MS: Liquid chromatography-mass spectrometry is an analytical chemical method known for its sensitivity in food testing. It uses HPLC techniques to test selected classes of plant protection products, such as carbamate and phenylurea pesticides, and is capable of separating mixtures and testing for each individual component with great precision, detecting even the smallest traces.
• GC-MS: Gas chromatography-mass spectrometry is a method used to separate volatile organic compounds and pesticides. This is done to detect pollutants in the air and to test for vapor intrusion. It is capable of detecting trace compounds and is used to detect pesticide residues or allergens.
• MS/MS: Tandem mass spectrometry is a method in which two mass spectrometers are coupled with an additional reaction step to increase their accuracy and reliability when testing chemical samples. This multi-method approach is commonly used to analyze biomolecules such as proteins and peptides in food.

Food, dietary supplements or natural cosmetics may contain crop protection product residues. These products are routinely analyzed for pesticide residue limits.

High quality products for your customers

If a product contains excessive residue levels, this means a reduction in quality for your product, which can be associated with (expensive) recalls and loss of image. Tentamus helps manufacturers to maintain their reputation by avoiding recalls and bringing high quality products to the market for your customers. This is done by ensuring that your products comply with all regulations by only containing maximum allowable residue levels.

Samples are drawn randomly either by you or by one of our samplers. During transport, sample freshness is maintained by using airtight plastic bags that prevent cross-contamination and desiccation of products. A cold chain is also maintained for goods that require refrigeration by using ice packs or dry ice.

Tentamus operates a global network of accredited laboratories that analyze food, dietary supplements, cosmetics and pharmaceuticals. In this way, we ensure that the legally required residue limits are not exceeded.

Although the Tentamus Group has evolved into a global company, we also pride ourselves on providing local and individual support to our customers. With our free sampling service, a team of dedicated experts and highly accurate technologies such as LC-MS/MS or GC-MS/MS, even the smallest traces of crop protection products can be detected.

The following laboratories of the Tentamus Group provide residue analysis: