Wednesday, April 16, 2014

ICP-AES Video Report

The Chem 312 students have finished their video report on the results of our ICP-AES analysis of the water samples. This video is designed to introduce our 6th grade partners to the idea of atomic emission and how it can be used to quantify metals in water samples.

For some of the lower abundance analytes (like heavy metals) the results suggested some drift or other source of error, and we were unable to quantify the concentrations of the metals. However, we did obtain useable results for metals that were present in high concentrations, such as sodium, potassium, and calcium. Based on our results, we will revise our procedure for next year so that next time we can quantify all the analytes of interest.

Sunday, March 23, 2014

ICP-AES Analysis

The results of the ICP-AES analysis are coming in. Both the students and I have been impressed with the dynamic range of the instrument. The students will quantify the most abundant elements as well as heavy metals, As, Cd, and Pb.

David and Mac did analyses of the most recent batch of water samples.

Sunday, March 2, 2014

The Supplies

For the 6th grade students colorimetric tests, we are using the LaMotte Urban Water Quality Test Kit, available from Amazon and Acorn Naturalist.

To help the students perform the tests, we developed a worksheet and slideshow based on the instruction manual that comes with the kit.
The kit is easy to use, results in exciting color changes for positive results, and takes only about 5 minutes per test. The 40-mL water samples collected by the 6th graders are suitable for about 5 of the tests included in the kit.
For the instrumental analysis students' lab, we are analyzing the water samples on a Thermo Iris II Inductively Coupled Plasma Atomic Emission Spectroscopy instrument (ICP-AES). 19-element and 7-element standards were obtained from CPI International and diluted in 2% nitric acid to create a series of standards: 100, 10, 1, 0.1, 0.01 ppm.

The Samples

I-Chem SS236-0040 Borosilicate Glass 40mL Clear Vial, Processed (Case of 72)

6th grade students from Ms. Laura Thompson's class at HMTCA collected water samples from the Connecticut River watershed around greater Hartford this fall. The students collected the samples in borosilicate I-Chem vials and labeled them with their names, the date, and the location where the sample was collected. We then stored the vials until this winter, when the 6th grade students began their water analysis unit and the instrumental analysis course is offered at Trinity College.

The Project

Students from the instrumental analysis class at Trinity College are partnering with about 100 6th grade students from Hartford Magnet Trinity College Academy to collect and analyze water samples from the Connecticut River watershed. In celebration of the 75-year history of the Division of Analytical Chemistry, this activity includes both classical wet analytical chemistry techniques (performed by the 6th graders) and advanced instrumental analysis (performed by the undergraduates).
This fall, the 6th grade students collected water samples from various locations in the Connecticut River watershed. In the spring semester, as a capstone project at the end of the 6th grade unit on water quality, the 6th grade students are performing water quality testing on their samples using a kit to measure levels of chlorine, iron, sulfate, nitrate/nitrite, as well as pH. The instrumental analysis students are guiding the 6th grade students through these tests and assisting them in selecting a subset of samples for trace metals determination by ICP-OES. The instrumental analysis students will then analyze selected samples for trace metals by ICP-OES. In lieu of a lab report, the instrumental analysis students will present their results, along with a grade-level appropriate explanation of ICP-OES, to the 6th grade students.

This project offers senior analytical chemistry students the opportunity to introduce the field of analytical chemistry and its environmental applications to a diverse group of local 6th graders, engaging undergraduates in experiential learning and community outreach.  In turn, the project’s activities complement the 6th grade science content standards on water quality, offer middle-school students an opportunity to learn and become comfortable in a college laboratory setting, and experience, firsthand, the impact of analytical chemistry.