Sampling Protocol: Do It Right
There’s a lot at risk involved in working with grain: equipment failure, facility catastrophe, supply chain irregularities, personnel well-being, and countless other issues before you even consider the commodity. Then there’s the grain itself. On one hand, it’s grown in a field with variable moisture conditions and other risk factors conducive to mycotoxin infection. On the other hand, buyers want to ensure that they know if a crop is GMO (made from genetically edited seeds) or not, and if so, which traits are present.
By the time the grain reaches the probe station, a lot of risk has already accumulated. It is for this reason that solid sampling protocol is essential to maximize the effectiveness of testing. Without good protocol, you run the risk of getting it wrong: accepting grain you shouldn’t and disappointing your downstream customers because they received mycotoxin contaminated, or GMO-positive, products from you.
Let’s say you run a test and it comes back high. Moreover, the grower drove their truck to a competitor and got a different result. What just happened? In a word, sampling. While you can’t grind a whole load, you have to take a quality sampling that’s as representative of the entire load as possible.
How do you know if that sample represents the truth? You may not like the answer, but there’s always error when it comes to sampling: the sample is never a perfect representation of the whole; but there are things we get can do to make sure we as close as we possibly can:
- In sampling, size matters, and bigger is always better. For example, by going from a 200g sample to a 1000g sample for non-GMO soybeans, the confidence level goes from 80 to 95% based on sampling studies we conducted with one of our customers.
- Probing: whether you do it by hand or with a pneumatic probe, you want to hit at least six locations in a truck and make sure the probe is the appropriate length to get to the bottom of the container. Insert it at an angle with the slot closed. With the slots up, open the probe and move it up and down twice. Close the probe and continue. You want to avoid spout lines, because fines and contamination are highest in those locations.
- Use a diverter for your sample. This increases the randomness of the sample you are taking and will make it more representative of what you are testing, be it truck, barge, or other vessel.
- If something seems a little off about this sample or test, the absolute best thing to do is to re-probe and run a second test, taking the average of the two tests. Do not “cherry pick” and take the result you like better. If that’s not an option, the next best choice would be to test a different portion of the sample you collected.
We occasionally hear from a customer who’s frustrated that our test isn’t working right for them. When we explore their test protocol, it turns out they weren’t following easy-to-implement, and vital, best practices. Do it the right way every time…here’s how to avoid confusion and get the best results:
- Print the test-specific QuickGuide (single-page instruction sheets) that we make for our most popular tests. Attach it to the wall above where you run your tests.
- Do you run Vom, Afla, and Fumonisin, or any combination of those three? Use Common Extraction. One sample prep will get you three results, keeping it simple.
- Review your standard operating procedure (SOP). Are you creating extra steps by storing bags in the wrong cabinet? Can you pre-measure water for one day’s testing? Members of our team have been to hundreds, perhaps thousands, of probe stands; no two are alike. Think about how you move around your testing area, and put the instruments you use where you need them. Label them with permanent marker so you don’t mistakenly grab the wrong item. There’s no limit to how much you can improve your SOP. We know because we regularly review and streamline our own; but in your environment, you’re the expert.
- Calibrate your grinder. Did you know that the specification for GMO grind is 60-70% through a #20 mesh sieve, but over 95% is required for mycotoxin testing? It is so important to get all the mycotoxins into solution as quickly as possible and the best way to do that is to perfect your grind. How do you know you’re hitting those ranges? Use a #20 sieve and weigh out 100g of kernels. Grind them as you normally would, and if 65g goes through the sieve and 35g remain, you’re all set for a GMO test.
If you have any questions about protocol, what is specific to you and your testing, or if you want to review it with someone, please give our Technical Service team a call at (866) 408-4597 x2. They’re always happy to hear from you and are genuinely invested in your success.
We have the highest quality standards in the industry. We take out all the stops to make sure every lot that leaves the building will perform exactly like the one that just left. Once you get that all-important sample extract, it doesn’t matter which strip in your EnviroLogix kit you use, the result is going to be the same.
Our pledge to you is to provide consistent and accurate tests you can rely on, season after season. Above all we want you to be fair…fair to your suppliers and fair to your customers. The best way we can do that is to make sure you understand how to test the right way and to provide you test solutions you can rely on.