Home Interviews THMG106 – Wet Chemistry Introduction with Todd Burton

THMG106 – Wet Chemistry Introduction with Todd Burton


In this episode, Bob discusses wet chemistry and HazCat® with Todd Burton.

Complete Show Notes

2:35 What is HazCat®?

  • Developed back in the 1980s when a white powder was spilled on the Golden Gate Bridge
  • They had no way of identifying the powder back then, which had an economic impact because they closed the bridge
  • HazCat® is a cookbook for chemists – follow the recipe and interpret the color of the end result
  • System uses wet chemistry to identify solids or liquids – essentially a backup system for blind spots in IR metering technology (i.e. sodium chloride)
  • Can identify a liquid or solid in 30-45 minutes maximum
  • Designed to identify the 200 most common substances you’ll find on road or rail
  • You need half to a third of a test tube of the substance, which is more than you need with IR
  • Kits are relatively inexpensive and allow you to identify the 20% of substances your meters can’t

8:55 Bob and Todd’s Wet Chemistry Liquid Experiment

  • Set up a table with a bunch of racks of disposable test tubes and denatured alcohol
  • Had a whole kit of different spoons, clamps, clips, re-agents, pH paper, etc. and a propane torch
  • Todd gave Bob an unidentified liquid and had him follow the HazCat® wet chemistry flow chart
  • Bob asked the questions indicated on the flowchart and checked out the accompanying book, which told him what he needed for the experiment
  • Three main tests in the kit:
    • Oxidizer test – if yes, you go into oxidizer land
    • Water solubility test – if yes, you go into organic things that float land
    • Thermal analysis test – if yes, you go into things that burn land
  • Bob learned that the unidentified liquid was nitric acid because…
    • The oxidizer test was positive
    • It dissolved completely in water
    • It had a strong acid pH test result
  • When taken together, these results moved them into the liquid acids chart
  • The whole testing process took Bob 15 minutes, and he’s a novice at wet chemistry

18:20 Bob and Todd’s Wet Chemistry Solid Experiment

  • Todd presented Bob with an unidentified solid that looked like chunky crystals of sea salt
  • Recommended questions from the chart and book:
    • Is it an enclosed glass bottle?
    • Is it fibrous?
    • Is it black or solid?
    • Is it pyrophoric?
    • Does it appear to be inert?
  • Based on the answers to these questions, they moved on to the oxidizer test – result was “any other reaction,” which meant it was oxidizer negative
  • Ran the acid test next – didn’t produce any concrete answers
  • Proceeded to the water solubility test – substance dissolved
  • Ran the pH test next – substance was relatively neutral (4-9)
  • Moved onto thermal analysis – took a metal rod and a Q-tip with hydrochloric acid, swabbed the crystals, and tried to burn them
  • Looked for thermal ignition – can the vapors coming out of the test tube be lit on fire? This determines whether it’s organic, inorganic, or an oxidizer
  • Followed that up with an ammonium salts test – brought them to the conclusion that the substance was some kind of iodide
  • Lit the substance on fire, which produced a lavender flame – checked the book and learned that the mystery substance was potassium iodide

31:25 Where to Take Classes and Where to Find Todd


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