4103FSBMOL - Practical 2 - UV-Vis Analysis.

Question 1

What suspected drug were we trying to identify in the sample in this practical?

Answer 1

Ketamine.

Question 2

How quickly can date-rape drugs act?

Answer 2

Within 20-30 minutes.

Question 3

What effects can date-rape drugs cause?

Answer 3

• Loss of Inhibitions.
• Muscle Relaxant.
• Sedative.
• Loss of Will to resist.
• Anterograde Amnesia (inability to form memories).

Question 4

How long do effects last when spiked with Ketamine?

Answer 4

30-45 minutes.

Question 5

What is the name of the relaxation state for low Ketamine Concentrations?

Answer 5

“K-Land”.

Question 6

What effects can High Ketamine Concentrations cause?

Answer 6

Dream like states, visual hallucinations, sensations of floating out your own body, confusion, delirium and anterograde amnesia.

Question 7

What sensation does “K-hole” form?

Answer 7

Near Death Experience.

Question 8

What is classed as a Low Concentration for Ketamine?

Answer 8

10-75mg/500ml.

Question 9

What is classed as a High Concentration for Ketamine?

Answer 9

100-250mg/500ml.

Question 10

What is classed as a “K-hole” Concentration for Ketamine?

Answer 10

500mg/500ml.

Question 11

How can UV-Visible Spectroscopy be used to analyse colourless solutions of Ketamine?

Answer 11

When the colourless camples absorb UV light, electrons are excited from ground to excited state to make absorption happen in the UV region.

Question 12

What Law is UV-Visible Spectroscopy goverened by?

Answer 12

Beer-Lambert Law.

Question 13

What does the Beer-Lambert Law state?

Answer 13

Absorbance is proportionate to Concentration.

Question 14

What is the Formula for the Beer-Lambert Law?

What does each symbol/ letter stand for?

Answer 14

A = εcl

• A = Absorbance.
• ε = Molar Extinction Coefficient.
• c = Concentration.
• l = path length.

Question 15

What is the name of the piece of equipment used in this practical?

Answer 15

UV-Visible Spectrophotometer.

Question 16

What were the standard solutions prepared in by the technicians?

Answer 16

5% ethanol solution.

Question 17

How much did we have to dilute the Crime Scene Sample down by?

Answer 17

1 in 25 diluted sample using 5% ethanol.

Question 18

What scanning range do we need to use on the UV-Visible Spectrophotometer?

Answer 18

200-350nm.

Question 19

What chemical do we need to use as a blank for Practical 2?

Answer 19

Ethanol solution.

Question 20

What modes on the UV-Visible Spectrophotometer do we need to select?

Answer 20

• Wavescan.
• Single Wavelength Mode.
• Absorption.
• No prompt.

Question 21

What do each of the buttons do on a Spectrophotometer?

Answer 21

• Blue - Blank Mode.
• Green - Scan Sample.
• Red - Back to Main Menu.
• 2 - Print Result.

Question 22

What concentration was the stock solution of Ketamine used?

Answer 22

100µg/ml in ethanol.

Question 23

What wavelength do we have to set the Spectrophotometer to measure the Absorbances of the Blank and Standards?

Answer 23

220nm.

Question 24

What do we have to plot on the y-axis of the graph?

Answer 24

Absorbance (no units - wavelength 220nm).

Question 25

What do we have to plot on the x-axis of the graph?

Answer 25

Ketamine Concentration (µg/ml).