In a 2019 study, a US advocacy group found trace amounts of the weed killer glyphosate in 14 out of 15 popular beers that were tested.

The study found that Tsingtao beer contained 49 parts per billion (ppb) of the chemical; Corona, Miller Lite and Budweiser had between 25 and 30 ppb; Guinness and Heineken contained about 20 ppb and beverages from Stella Artois and Sam Adams had trace amounts.

Taking into account current regulations and questions surrounding the accuracy of this study, these findings dont necessarily mean that these pesticide residues are dangerous. There are still unknowns, and the danger of glyphosate is a hotly contested topic.

WHAT IS GLYPHOSATE?

Glyphosate is a non-selecive pesticide and herbicide used to kill weeds and grasses. The chemical works by blocking an enzyme essential for plant growth. Glyphosate is widely used in agriculture and forestry, and it has become one of the most commonly used residential herbicides for lawn and garden care.

Concerns about glyphosate linger, however, as several studies of both humans and animals have found that chronic exposure to the herbicide could be toxic. In 2015, the International Agency for Research on Cancer (IARC), a branch of the World Health Organization, classified the chemical as a probable human carcinogen, noting that epidemiologic evidence suggests it is linked to non-Hodgkins lymphoma. IARC also concluded that there was “strong” evidence of genotoxicity in both “pure” glyphosate and glyphosate formulations.

Despite the health risks linked to glyphosate, its still one of the most commonly used weed killers in agriculture. Charles Benbrooks study reveals that in the US, 1.8 million tons of glyphosate have been applied since its introduction in 1974. The study also found that worldwide, 9.4 million tons have been sprayed onto fields. To put things into context, thats filling an Olympic-size swimming pool 2,300 times. Whats even more concerning are studies that have detected traces of glyphosate residues in humans and animals due to chronic exposure.

GLYPHOSATE IN SOUTHEAST ASIA

Similar to other regions of the world, glyphosate is commonly used in Southeast Asia. The growing awareness of its possible dangers has led countries such as Thailand to restrict domestic application of the chemical for crop cultivation. However, while the countrys maximum residue limits (MRLs) are compliant with Codex international food standards for the residue of glyphosate in food and food products, the government does not impose any MRLs for glyphosate in feed ingredients and products.

In Indonesia, glyphosate is the most common herbicide used in palm oil plantations and other types of agriculture. Indonesia is the second largest producer of palm oil after Malaysia, with the 2 countries accounting for 80 percent of the worlds total production of palm oil. In 2020, the palm oil plantation in Indonesia had reached 6 million hectares, with the government planning a target of 20 million hectares. This means that vast amounts of chemicals, particularly glyphosate, have been poured into the ground and continue to pollute the soil.

In addition, on April 24, 2020, the Vietnamese Ministry of Agriculture and Rural Development (MARD) issued Circular 06/2020, which deactivates the glyphosate ban issued under MARDs previous Decision 1186 and extends the use of glyphosate products to June 30, 2021. Vietnams glyphosate MRLs comply with Codex standards as prescribed in the Ministry of Healths Circular 50/2016 (GAIN Report VM7026).

Because of the changing regulations around glyphosate and the current status of its use in Southeast Asian countries, it is important to test for the level of glyphosate in various matrices such as food, soil and water.

DETECTING GLYPHOSATE IN BEER

Traces of glyphosate have been found in surface water, in human urine and breast milk, and in many foods, such as bread, breakfast cereals, dairy and beer. When it comes to beer, glyphosate may have been sprayed directly onto the barley used for brewing or it may have seeped into the soil or water or drifted from nearby farms. The possibilities can be endless.

Monitoring glyphosate in food and water sources can be a significant challenge. Glyphosate is a highly polar and small organic pesticide, and polar pesticides are not amenable to standard SPE extraction procedures. In addition, some polar pesticides are poor ionizers and do not retain or separate on most reversed phase columns well. Current analysis methods rely on labor-intensive derivatization and cleanup steps.

SCIEX has developed a technical note that details an analytical method for underivatized glyphosate and its metabolite aminomethylphosphonic acid (AMPA) in water and beer samples using LC-MS/MS. In this experiment, we have achieved LOQs as low as 100 ng/L in water and 200 ng/L in beer by utilizing large-volume injection and high-sensitivity detection with the QTRAP 6500+ LC-MS/MS System. The method was also successfully applied to the evaluation of 40 different popular homemade beers.

Are you interested in reading more about trace-level detection of glyphosate in water and beer samples using LC-MS/MS? Download a free copy of the technical note on this topic for more details on the method used and the amount of glyphosate detected in 40 different beers.

by Yip See Chung, Field Application and Market Development Manager, SCIEX