Spring is allergy season and as I made my customary trip to the farmers market to stock up on local wild flower honey this last weekend, I could not help but notice the honey stand was considerably smaller than I remember it in past years. In addition, the price of honey was at least 20% higher, if not more. My thoughts turned to the cause of this problem: the dying of these diligent pollinators, how this affects the food chain, and, of course, what chemists can do to help. I started to wonder if sample preparation techniques, such as the Accelerated Solvent Extraction (ASE) technique could be used to extract pesticides from bee-based products, such as bee pollen. But, before I talk about analytical techniques, I thought I would give a brief overview on what is going on with bees and pesticides.
Bee Colony Collapse Disorder
A recent blog article posted in Scilogs titled, Spring is Here but Where are all the Bees? – The latest on Colony Collapse Disorder (CCD) discusses bee colony collapse disorder and the wide use of a class of insecticides, neonicotinoids, which are causing the largest number of honey bee deaths. Neonicotinoids cause bees to behave mysteriously and makes bee colonies descend into chaos during the worst season for the insects to be active: winter. During the winter seasons, a colony affected with CCD dissolves, with the hive’s workers leaving the hive, only to die in the unforgiving winter. The European Union banned neonicotinoids in 2013 and in the United States; the Environmental Protection Agency (EPA) is unlikely to approve new neonicotinoid pesticide use as it continues to assess pesticide safety for bees. The toxicity of neonicotinoids to bees and other insects has brought them the most attention thus far and has dominated recent concerns of regulatory institutions worldwide. The serious risk to bees should not be understated, as one-third of the U.S. diet depends on these insect pollinators. The American Bird Conservancy (ABC) assessment makes clear, however, that the potential environmental impacts of these pesticides goes well beyond bees. Their report urges EPA to expand its registration review of neonicotinoids to include birds, aquatic invertebrates, and other wildlife.
An ABC article, titled, Birds, Bees, and Aquatic Life Threatened by Gross Underestimate of Toxicity of World’s Most Widely Used Pesticide, (link to article) quotes Cynthia Palmer, Pesticide Program Director, as saying, “It is clear that these chemicals have the potential to affect entire food chain. The environmental persistence of the neonicotinoids, their propensity for runoff and for groundwater infiltration, and their cumulative and largely irreversible mode of action in invertebrates raise significant environmental concerns.”
Classification of Pesticides
Pesticides are classified into groups based on their chemical structure (organophosphates, pyrethroids, organochlorines, carbamates, neonicotinoids etc.), mode of action (systemic, contact), target (insecticides, acaricides, herbicides, fungicides, bactericides, nematicides) and synthesis (synthetic or natural). The residues of pesticides detected in products are classified in the groups of insecticides (organochlorines, organophosphates, carbamates and neonicotinoids), acaricides, fungicides and herbicides. Organochlorine pesticides are persistent organic pollutants (POPs), a class of chemicals that are ubiquitous environmental contaminants because they break down very slowly in the environment and accumulate in lipid rich tissue such as body fat. Many organochlorine pesticides are endocrine-disrupting chemicals, meaning they have subtle toxic effects on the body’s hormonal systems.
Application Brief 152, titled, Extraction of Organochlorine Pesticides from Oyster Tissue Using Accelerated Solvent Extraction, (downloadable PDF) uses one of our Accelerated Solvent Extraction system (Thermo Scientific Dionex ASE 350 Accelerated Solvent Extractor system) and a sample preparation polymer (Dionex ASE Prep MAP polymer) designed to increase the extraction efficiency of wet samples during in-cell extractions. The method is simple and reliable and extracts organochlorine pesticides from oyster tissue followed by gas chromatography analysis.
For more information on the polymer and other ASE applications, consider watching this hour long on-demand webinar titled: Increase Productivity with Automated Sample Preparation, (link to webinar registration page). You also might want to check out applications developed for extraction of organophosphorous pesticides, PolyChlorinated Biphenyls (PCBs), Polyaromatic Hydrocarbons (PAHs) and chlorinated herbicides using the ASE technique.
Like what you are learning?
For more information on ASE consumables, check out the following:
- Product Spotlight on ASE Prep MAP (downloadable PDF)
- Thermo Scientific Dionex ASE Prep Sorbents (downloadable PDF)
Is pesticide extraction and analysis of interest to your laboratory? If so, I would like to hear your thoughts and experiences.