When Alkemist Labs (Garden Grove, CA) added pesticide testing to its suite of services earlier this year, the company stated it was 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 (U.S. Pharmacopeia) 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, according to the company.

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 percent requires two additional analytical runs,” said Lab Director Anthony Fontana, PhD. “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 As (certificates of analysis) 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? According to Alkemist, depending upon how a company has set their specifications, they may be out of compliance with cGMPs (current good manufacturing practices). 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.”

For more information, visit www.alkemist.com.