The state of California demands the analysis of pesticides, mycotoxins, and cannabinoids in all types of cannabis-derived goods [1]. For that reason, reliable workflows for the easy determination of these analytes in diverse matrices are highly desired. Gummies are a very popular cannabis edible, and their composition makes them a highly complex matrix. In this work, we describe a complete workflow for the analysis of California pesticides, mycotoxins, and cannabinoids in gummies using a single extraction procedure.<\/p>\n\n\n\n
Edibles infused with cannabis or cannabidiol (CBD) are growing in popularity with cannabis consumers. In terms of testing, potency analysis of edibles is mandatory in all states where lab testing is a requisite. In addition, in the state of California, determination of contaminants, such as pesticides and mycotoxins, in edibles and other cannabis-derived goods is also a requirement. Due to the broad variety of edibles available in the market, different analytical strategies should be pursued in order to obtain reliable analytical data for all analytes of interest in all matrices. Among the various types of cannabis edibles, gummies present unique challenges for cannabis testing labs.<\/p>\n\n\n\n
Gummies are a type of sticky matrix typically made of ingredients such as sugar, starch, pectin, and gelatin. Due to their composition, sample preparation strategies for potency testing usually include a sample solubilization step in solvents like water or DMSO or, alternatively, large volumes of solvents like methanol may be used. Following sample homogenization, cannabinoids are quantified via HPLC-UV by injecting diluted extract either directly or following a salting-out step using QuEChERS salts. As for the analysis of contaminants like pesticides and mycotoxins in gummy matrix, publicly available information is quite scarce, with only one report showing semiquantitative data for 35 pesticides using QuEChERS [2].<\/p>\n\n\n\n
In this work, we provide a robust workflow for the quantitative determination of the California list of pesticides, mycotoxins, and cannabinoids in gummy samples. The optimized sample preparation methodology involves sample solubilization followed by an extraction step using acidified acetonitrile, and a salting-out step using EN QuEChERS salts. For the analysis of cannabinoids and LC-amenable contaminants, a simple dilution was conducted prior to injection. Whereas, for the GC-amenable pesticides, the use of a dSPE sorbent mix including primary\/secondary amine (PSA), graphitized carbon black (GCB), and magnesium sulfate was necessary before analysis. Overall, the proposed workflow for the analysis of pesticides, mycotoxins, and cannabinoids in cannabis gummies provides satisfactory results in terms of linearity, accuracy, precision, and limits of quantitation (LOQs).<\/p>\n\n\n\n
After preliminary testing of various experimental parameters, the following workflow was implemented (Figure 1). Chopped gummies (1 g) were weighed into a 50 mL tube (cat.# 25846), and 5 mL of water was added. Then, the samples were vortexed vigorously until the gummy pieces were solubilized. The sample solution was then fortified with target analytes and\/or internal standards (internal standards were used only for contaminant analysis, not for potency testing) as appropriate and vortexed again for 30 seconds. Next, 5 mL of acetonitrile acidified with acetic acid (1% v:v) was added, and the samples were vortexed another 30 seconds. A pouch of European EN 15662 Q-sep QuEChERS extraction salts (cat.# 25849) was added, and the sample was vortexed again and then centrifuged for 5 minutes.<\/p>\n\n\n\n
For potency testing, 100 \u00b5L of the sample extract was mixed with 900 \u00b5L of 25:75 water:acetonitrile, and 2 \u00b5L were analyzed by LC-UV. For the LC-amenable contaminants, 750 \u00b5L of the sample extract was mixed with 250 \u00b5L of water, and 2 \u03bcL were analyzed by LC-MS\/MS. For the GC-amenable contaminants, 1.9 mL of extract was transferred to a Q-sep QuEChERS dSPE tube containing pre-weighed PSA, GCB, and magnesium sulfate sorbents (cat.# 26217). After vortexing and centrifuging, 500 \u03bcL of extract was mixed with 500 \u03bcL of 1% acetic acid in acetonitrile, and 1 \u03bcL was analyzed by GC-MS\/MS.<\/p>\n\n\n