Researchers from the Litoral National University and the United States Department of Agriculture have expanded the current sample preparation method to meet the reproducibility and efficiency needs of the marijuana sector.
With the legalization of hemp in America, convenient and fast techniques are necessary for evaluating residual pesticides on plants to replace current, cumbersome methods.
Constantly and accurately evaluating plants for pesticide deposit can be expensive and time-consuming.
The present sample preparation technique, dubbed QuEChERS (quick, easy, cheap, efficient, rugged, and safe), initially created to determine pesticide deposits on vegetables, fruits, and non-food plants such as tobacco, has been utilized for marijuana since 2014.
It’s a two-phase procedure: analyte extraction (mostly in acetonitrile) before the cleanup to eliminate compounds (pigments, fatty acids, and sugars) that may tamper with the evaluation.
In the marijuana case, these compromising compounds include terpenes and cannabinoids.
The writers updated QuEChERS, making it feasible to test a broader product range apart from pesticides, such as fungal and plant toxins and environmental contaminants. They authenticated the sample preparation technique for a hundred and six pesticides tested in Northern United States.
The LOQ (limit of qualification) for a significant number of tested pesticides was <10ng/g, and 2.8 percent false negatives. This LOQ is lower than the limit set by the California Cannabis Control Bureau, which places the detection cap at <100ng/g.
The upgraded technique can be utilized on whole plant material, oil, powders, and pellets. However, it’s not functional on dried hemp flowers and plants. After sample preparation, samples are evaluated using top-tier chromatography-tandem liquid mass spectrometry and gas mass spectrometry.
Despite this sophisticated equipment, pesticide sampling approaches are time-consuming, tedious, and need expertise. The procedure needs to be repeated severally for every pesticide under study. For instance, in California, marijuana has to be tested for sixty-six different pesticides.