Prescription for CrimeTM Drug Testing Lab 2 solutions

Known GC-MS data sheets Oxycodone Amphetamine Methamphetamine Cocaine Ketamine

This graph is the GC plot for oxycodone

This graph is the GC plot for oxycodone X-axis: time the material is on the column in minutes

Y-axis: peak height in mcounts This graph is the GC plot for oxycodone X-axis: time the material is on the column in minutes

may be a single component, but more testing is required to make sure this isn’t a cluster of components that haven’t separated

This graph is the MS plot

This graph is the MS plot X-axis: mass to charge ratio of the sample LOW mass HIGH charge HIGH mass LOW charge

Y-axis: percent absorbance of the sample This graph is the MS plot X-axis: mass to charge ratio of the sample LOW mass HIGH charge HIGH mass LOW charge

multiple components, the “fingerprint” for this sample LOW mass HIGH charge HIGH mass LOW charge

What is our unknown sample? Possibilities: Oxycodone Amphetamine Methamphetamine Cocaine Ketamine

What is our unknown sample? Oxycodone Peaks at: 8 and 9 min Peaks at: 23 min The real unknown was too confusing, so I removed it and had you use the concentrations of the unknown. 43, 56, 58, 91, 150 70, 230, 315, 316, 317

What is our unknown sample? Oxycodone

What is our unknown sample? Amphetamine Peaks at: 8 and 9 min Peaks at: 7 min 43, 56, 58, 91, 150 42, 44, 91,136

What is our unknown sample? Amphetamine

What is our unknown sample? Ketamine Peaks at: 8 and 9 min Peaks at: 16.7 min 43, 56, 58, 91, 150 180, 182, 238, 240, 239

What is our unknown sample? Ketamine

What is our unknown sample? Cocaine Peaks at: 8 and 9 min Peaks at: 6.7, 11 min 43, 56, 58, 91, 150 42, 82, 122, 150, 152, 156, 181

What is our unknown sample? Cocaine

What is our unknown sample? Methamphetamine Peaks at: 8 and 9 min Peaks at: 8 min 43, 56, 58, 91, 150 56, 58, 91, 150

What is our unknown sample? MATCH! Unknown Methamphetamine Peaks at: 8 and 9 min Peaks at: 8 min 43, 56, 58, 91, 150 56, 58, 91, 150

What is our unknown sample? Methamphetamine No 9 min peak No 43 peak Maybe the sample was cut or we are seeing additional byproducts of the manufacturing process?

0.25 milligrams of meth per milliliter of solvent in the sample Lab 2, part B Four concentrations of meth in this analysis: 0.25 mg/ml 0.50 mg/ml 0.75 mg/ml 1.00 mg/ml 0.25 milligrams of meth per milliliter of solvent in the sample

Measure the peaks of four concentrations with a ruler (mm) 0.25 mg/ml of meth GC peak at 8 min Baseline to peak measurement: 20.5 mm

Measure the peaks of four concentrations with a ruler (mm) 0.50 mg/ml of meth GC peak at 8 min Baseline to peak measurement: 47 mm

Measure the peaks of four concentrations with a ruler (mm) 0.75 mg/ml of meth GC peak at 8 min Baseline to peak measurement: 63.5 mm

Measure the peaks of four concentrations with a ruler (mm) 1.00 mg/ml of meth GC peak at 8 min Baseline to peak measurement: 89 mm

Make a scatter plot of the peaks in Excel

Make a scatter plot of the peaks in Excel Input your measurements from the provided GC chart peaks

Make a scatter plot of the peaks in Excel Insert tab, scatter chart button, scatter with only markers button

Make a scatter plot of the peaks in Excel Select the chart, design tab, select data button

Make a scatter plot of the peaks in Excel Add a legend entry (series)

Make a scatter plot of the peaks in Excel Choose the series name (cell A1)

Make a scatter plot of the peaks in Excel Choose the series name (cell A1)

Make a scatter plot of the peaks in Excel Choose the series x values (cells A3:A6)

Make a scatter plot of the peaks in Excel Choose the series y values (cells B3:B6)

Make a scatter plot of the peaks in Excel Click OK

Make a scatter plot of the peaks in Excel Right click one of the data points and select “add trendline”

Make a scatter plot of the peaks in Excel Choose Linear, check display equation and r-squared value on chart

Make a scatter plot of the peaks in Excel Delete the legend

Make a scatter plot of the peaks in Excel Move the equation so you can read it easier

Make a scatter plot of the peaks in Excel Layout tab, axis titles button, primary horizontal axis title, title below axis

Make a scatter plot of the peaks in Excel Double click the axis title and re-name it “concentration of known solution (mg/ml)”

Make a scatter plot of the peaks in Excel Layout tab, axis titles, primary vertical axis title, rotated title

Make a scatter plot of the peaks in Excel Double click the axis title and re-name it “peak height (mm)”

Calculate the concentration of the unknown solution (meth) Our equation from the trendline: y = 88.8x – 0.5 peak height = 88.8 * concentration – 0.5

Calculate the concentration of the unknown solution (meth) Solve for x (concentration): y = 88.8x – 0.5 y – 0.5 = 88.8 x (y – 0.5) / 88.8 = x concentration = (peak height – 0.5) / 88.8

Calculate the concentration of the unknown solution (meth) The peak height for the unknown solution was 75.5 mm. Plugging this number into the concentration formula from the trendline, we get: concentration = (peak height – 0.5) / 88.8 concentration = (75.5 – 0.5) / 88.8 concentration = 0.844 mg/ml

Calculate the concentration of the unknown solution (meth) To get a sense of what is happening, we plot this data point [0.844 mg/ml, 75.5mm] on top of the concentration graph 75.5 0.844

Calculate the percentage of the drug (meth) Sample concentration: 0.844 mg/ml Original concentration: 2 mg/ml 0.844 mg/ml / 2 mg/ml = 0.422 = 42.2%

Calculate the quantity of the drug (meth) Drug concentration: 42.2% Mass of powder collected by police: 13g Drug quantity present: 0.422 * 13g = 5.48g