Alkemist Labs Warns Industry that Pesticide Testing is Often

Missing Two Analytes:

Inorganic bromide and Dithiocarbamates measured and reported as carbon disulfide (CS2)

Garden Grove, CA (July 5, 2022) –When Alkemist Labs added pesticide testing to their suite of services earlier this year, they were surprised that the reports several clients had been getting revealed that pesticides testing by some third-party labs is not as comprehensive as the clients had assumed.

<561> is the USP general chapter that encompasses articles of botanical origin, involving all botanicals in commerce. It addresses a lot of topics, but in terms of pesticides lists 70 reportable compounds covering 121 individual analytes.  Alkemist tests for the full USP panel, and assumed all other labs claiming to test USP <561> pesticide residue did as well. But it turns out that often they do not, and may not be transparent about it.

To cover the entire USP Panel, Alkemist conducts four separate assays using three different instruments: one run each of UPLC-MS/MS, APGC-MS/MS, and two runs of GC-MS/MS.

“Ninety eight percent of the compounds tested for UPLC-MS/MS and the APGC-MS/MS; the other 2% requires two additional analytical runs,” said Lab Director Anthony Fontana Ph.D. “What we have learned is that a lot of labs skip those, quite possibly because of the time and processing you need to run it. You are changing over the same instrument twice, each time to search for one more analyte, which can take half a day. Skipping these two runs only omits two analytes from an already lengthy report, so they may be easily overlooked.”

Alkemist Labs advises companies to carefully check their pesticide testing reports to ensure that results include Inorganic bromide and Dithiocarbamates measured and reported as carbon disulfide (CS2).  If these compounds are omitted, then USP <561> pesticides testing is incomplete.  From the reports Alkemist has seen, some C of A’s are transparent about the missing compounds, but others are not.  Sometimes the cost to the manufacturer doubles if those two last analytes are added to the test run.

Another practice Alkemist has seen is the use pf the phrase “USP <561> modified.” Usually the use of “modified” in relations to USP means that newer instrumentation or column technology is being used than described in the USP chapter.  However, USP <561> is not a detailed analytical method, but rather a table of pesticides that must be tested to confirm they are below the listed thresholds. So showing USP <561> Modified on a report appears to indicate that some pesticides are not being tested for at all.   

Why is this a problem? Depending upon how a company has set their specifications, they may be out of compliance with cGMPs.  This is a fundamental error that could be caught in an audit if they have set a spec they are not testing to.  And if companies are marketing their products that they do comprehensive pesticide testing but in reality are not, there is the risk of loss of consumer trust. There also may be a safety risk due to toxic pesticides that have not been screened for.

“I understand why some labs may use this practice, which would necessarily make testing more expensive, but it’s misleading,” said Elan Sudberg, CEO of Alkemist Labs.  “The industry has to be better than that.”

About Alkemist Labs

Alkemist Labs is an ISO 17025 accredited contract testing laboratory specializing in plant authentication, botanical ingredient identification, quantitative analytical services and contaminant screening for the Food & Beverage, Nutraceutical and Cosmeceutical industries. Located in a state-of-the-art facility in Garden Grove, California, Alkemist Labs offers clients a wide range of specialty research services to evaluate the identity, purity, and quality of botanical raw materials, dietary ingredients, and finished products. DEA registered 1, 2, 3n, and 4 for over 20 years, Alkemist is also approved to be on California Department of Food and Agriculture (CDFA) list for hemp testing. Alkemist Labs also produces a complete line of Composite Reference Botanicals (CRBs), critical tools for botanical identity verification. Since it was founded in 1997, Alkemist Labs has become the ideal “Partner for Quality” to companies interested in producing high quality natural products requiring independent, third-party analysis, Stability/Shelf-life studies, Certification of Analysis, and cGMP compliance.


Suzanne Shelton
The Shelton Group
Cell: 847-922-545

Join the Alkemist Newsletter