Background for Teachers
You now have samples from your field season tucked into your freezer, and it is time to submit the samples for analysis. Do not take them out until you’re ready to submit them. The turn-around time (the time the lab gets your samples to the time you get your results) for total nitrogen analysis is about four weeks. You should probably submit your samples immediately after you have returned from the field for the last time.
You will be submitting seven water samples to the lab for analysis. One of those samples must be a field duplicate (a field duplicate is a sample collected on the same sampling event, immediately after collecting the field sample, and collected in exactly the same manner… it allows the partnering scientist to ensure that the field protocol is followed in such a way that it produces replicable results).
The person at the lab who will analyze your samples may NOT be any of the scientists working on the project. It may be a lab technician. This person has essentially no idea what you are doing or why. You and your class are in charge of knowing what you are sending in. The only way you can track your samples is to know what you are sending in, what you are calling the samples (that sample ID).
Decide which samples, from which sampling events, you will be submitting. Each sample will have a unique sample ID on the label on the bottle (see Unit 4, Activity 2 Preparing for Sampling for an example)
Fill out a Chain of Custody form. This form tells the lab what you are submitting – again, the lab doesn’t know what we’re doing, so you need to give them the information.
Contact Acadia Learning staff or project scientist, Sarah Nelson, to arrange for samples to be either dropped off (by you), picked up (by us), or sent to the lab via FedEx. It is important that the lab has a heads‐up when things are arriving.
Whether samples are to be dropped off, picked up, or shipped, they’ll need to be delivered frozen, in a cooler with ice. The cheapest way to get ice is to make it in an empty water or soda bottle filled with water and put in a freezer. That will keep things cold enough for a short car ride or FedEx trip. Sarah will give specific details for each teacher’s situation – but be ready with the ice and a small cooler (which we will return).
- Successful transfer of water samples to lab for nitrogen analysis
- Students will determine which samples collected will best help them answer their research questions.
- Students will submit samples, accompanied by a Chain of Custody, to the lab for analysis.
Where does this lesson happen in the Project?
- This is the fourth lesson in Unit 4: Field Sampling to Support Your Claim. This activity concludes Unit 4.
- Print the Chain of Custody form
- Locate the samples that have been collected
- Have a packing/shipping box ready
- Chain of Custody form
- Cooler with ice packs
- Packing tape
- Student research questions
Handouts (see also Lesson Resources)
- As there is need for only ONE Chain of Custody form it is not listed as a handout
- Students must know where the samples were collected and their own questions
One class period. If you have more than one section of a class working on this project you may only have the classes decide which samples to send and then have one class do the paperwork and prepare the samples for delivery.
Doing the Activity
- Have your students review their questions, and the data requirements, as they wrote them in their research plan (from Unit 3).
- Have your students review the conditions under which all of the samples were collected and determine which ___ samples will best help them answer their research questions.
- Remove those samples from the freezer.
- Fill out the Chain of Custody form.
- Put the samples in the cooler with icepacks.
- Put the Chain of Custody in a zipper bag and tape it to the underside of the top of the cooler.
- Seal the cooler and address it to:_______ .
- Put the cooler in the location where you have arranged for it to be picked up (you will have already made arrangements for the delivery of the samples to the lab).
- Put the box in the location where you have arranged for it to be picked up (you will have already made arrangements for the delivery of the samples to the lab).
Ask students to think about how many data points they need to answer their questions.
Ask your students to design a research plan to capture seasonal or spatial change in a whole river system (anything seasonal or spatial) but they only have funds for three samples. This truly happens all the time in environmental sampling.
Lesson Extensions and Supplements
Students research Chains of Custody- whether for a criminal investigation or in sustainable forestry practices.
Chain of Custody form