Exploring Cyanide Research: Effects & Detection

1. Chemistry Research Team Starring: Matt Herring Deanne Seymour Bettylou Wahl And special guest Cyanide

2. What is Cyanide? • CN- • Common forms: HCN, NaCN, KCN • Found in foods such as Cassava, lima beans, almonds, and apples • Produced by certain bacteria and fungi • Enters the body through ingestion, inhalation, and absorption

3. Hydrogen Cyanide • Colorless gas • Almond scent • BP: 25.6 C • Enters the body through inhalation • Toxic gas present in cigarette smoke • Released in metallurgy, electroplating, metal cleaning processes and car exhaust • Used for fumigation of dry foods such as cereals, seeds, nuts, and tobacco • Used for disinfestation of buildings

4. Effects of HCN on the body DEATH • Chronic low exposure causes neurological, respiratory, cardiovascular, and thyroid effects • EX: difficulty breathing, heart pains, vomiting, blood changes, headaches • Long term exposure causes central nervous system effects • Weakness of digits, difficulty walking, dimness of vision, deafness • High levels of exposure in a short amount of time harms the brain and heart and may cause coma and

5. Cigarette Smoke • Cigarettes are a large source of cyanide • Cyanide is not present in actual cigarettes, but is found in the smoke • Cyanide levels in inhaled cigarette smoke range from 10 to 400 micrograms per cigarette

6. Thiocyanate • Cyanide is metabolized to thiocyanate through sulfuration with thiosulfate by mitochondrial rhodanese in the liver • Thiocyanate is present normally in human saliva in a [ ] of about 0.01% • Thiocyanate levels in saliva correlate with cyanide intake

7. Methods for determining cyanide and thiocyanate levels • HS-GC (head-space gas chromatography) • Spectrophotometric Konig method • Thiocyanate ion (SCN-) reacts with iron Fe3+ to yield FeSCN2+ complex which can be detected spectrophotometrically • The complex exhibits a red/orange color that becomes darker with greater concentration • UV-VIS is to measure the absorbency

8. Previous research and studies • Saliva Thiocyanate levels of smokers, non-smokers, and second hand smokers has been studied • Smokers have been found to have higher levels of thiocyanate • Cyanide applied to food given to animals

9. What needs to be done? • Testing the amount of cyanide intake from certain foods compared to tobacco smoke • Duration that cyanide is present in body after being exposed • Amount of cyanide in cigarette smoke compared things such as vehicle exhaust, metal industry emissions

10. Challenges • The cyanide left in mouth from cigarette smoke affects the amount of cyanide in saliva • Monitoring peoples’ diets for testing • Storing the samples • Getting a large enough sample size • Finding a strong control when there are many variables

11. Method for preparing saliva • Obtain 2.5 mL of saliva • Centrifuge at 12,000 rpm for 12 min • Remove and centrifuge clear liquid again at 12,000 rpm for 12 min • Add 0.5 mL of centrifuged saliva to 9.5 mL of 0.0019 M Fe(NO3)3 • Measure absorption at 448 nm in spectrophotometer

12. Establishing Standard Curve • Beer’s Law: A=abc • Used to determine the concentration from the experimental absorption level values • Established using three known concentrations of FeSCN as standards • Curve checked for accuracy

13. Standard Curve

14. The end