Presentation on theme: "QUESTION 2.. A. What is the composition of non-stick frying pan? Is there any reason to believe that fluoride may cause toxicity in this instance? (Hint:"— Presentation transcript:
A. What is the composition of non-stick frying pan? Is there any reason to believe that fluoride may cause toxicity in this instance? (Hint: what is the monomeric form of TEFLON)
polytetrafluoroethylene (PTFE), synthetic fluropolymer of tetrafluroethylene. Fluorocarbon solid high-molecular-weight compound consisting wholly of carbon and fluorine very non-reactive, partly because of the strength of carbon–fluorine bonds. Teflon
B. Perform experiment to see if significant amount of fluorides were released from the metabolites of the coating material, by comparing this metabolite against sevoflurane (non-toxic) and methoxyflurane (toxic) dosed at the same concentration in some test animals. What is the Nernstian slope and Econst for this fluoride detector, assuming standard temperature and pressure? Is it considered acceptable for accurate determination of fluoride concentration?
ΔE = Econst + RT/zF log Ci STEP ONE:Plot log[F - ] vs ΔE STEP TWO: Find equation of the linear line STEP THREE:Slope will be defined by RT/zF Slope of equation: Y1-Y2/X1-X2 = (-17.0 – 100) / (log 1.00 x 10 -3 – log1.00 x 10 -5 ) = -58.5 mV/M Under standard conditions, the ideal value of the slope will be about 59.1mV per 10-fold change in concentration Nernstian slope [F - ] (M)ΔE (mV) 1.00 x 10 -5 100.0 1.00 x 10 -4 41.5 1.00 x 10 -3 -17.0 Nernstian Slope
Plot of log[F - ] vs ΔE
E constant ΔE = Econst + RT/zF log Ci Econst = ΔE - RT/zF log Ci sub in values: E const = 100 – (-58.5)log(1.00x10 -5 ) = -192.5 mV
C. If the test sample gave a reading of 90 mV, what would be the concentration of fluorides released from this compound? Given that equal dose of administered sevoflurane (non- toxic) or methoxyflurane (toxic) gave the readings 88 and 30 mV respectively, what would be your response to Mrs Ting?
C assay < C non-toxic Teflon does not produce enough F- to be toxic! :D ΔE = Econst + RT/zF log Ci 90mV= -192.5mV -58.5log C assay C assay = 1.00 x 10 -4.83 88mV= -192.5mV -58.5log C non-toxic C non-toxic = 1.00 x 10 -4.79