Analysis

Question 1

What was your first test you performed?

Answer 1

I weighed the contents in the vial. I first took glassine paper, set it on the scale, then transferred the powder onto the paper and weighed the powder. I recorded in my case notes the net weight and transferred the powder back to its original vial.

Question 2

Do you see any indication on this envelope where you opened it?

Answer 2

Yes, along the edge here where it is initialed and the date when the evidence was sealed.

Question 3

What was the weight?

Answer 3

346.45 mg net

Question 4

What was your next test on the evidence?

Answer 4

I did a direct analysis of the powder using GC-MS & ATR-FTIR.

Question 5

How did you perform the direct analysis?

Answer 5

For GCMS I scooped a small amount of powder using a toothpick into a gc vial, added 1ml of methanol, and sealed the vial. The vial was then handed to the advisor who ran the vials and inputted the results on our laboratory google drive folder.

For the FTIR the neat powder was analyzed with the ATR accessory which allows for neat compounds to be analyzed.

Question 6

what do you mean by neat?

Answer 6

the substance had no solvent in it. It was just the pure powder.

Question 7

Who ran the samples?

Answer 7

The advisor, thulitha, ran the GCMS samples. I ran the ATR-FTIR samples under the supervision of thulitha. The spectra were uploaded by him onto the google drive folder for the lab.

Question 8

what does a GC-MS do?

Answer 8

A GC-MS is a gas chromatography with a mass spectrometer detector. The GC is an analytical instrument that separates out individual components of a mixture. These components leave the column one after another and enter the MS- mass spectrometer detector which analyzes the mass to charge ratio of the component. It then travels through the column and that time traveled is called the retention time.

Question 9

What does a ATR-FTIR do?

Answer 9

The ATR stands for attenuated total reflectance and is the accessory that allows for neat samples to be analyzed. It is attached to the FTIR, fourier transform infrared spectrometer.

FTIR analyzes a samples by measuring the range of wavelengths in the IR region that are absorbed by the material. The bonds and groups of bonds vibrate at characteristic frequencies and the sample absorbs the IR energy at diff. freq. which are characteristics of the molecule.

Question 10

Why did you use methanol in the direct analysis using the gcms?

Answer 10

Methanol is a common solvent used to dissolved the powder. It has a known early retention time, meaning it comes out of the column fast, and allows for less interference of analysis of the sample’s components.

Question 11

what are chemical spot tests?

Answer 11

it is presumptive, preliminary identification technique. generally the first step to identify the class of substance.

Question 12

how are the chemical spot tests analyzed?

Answer 12

the chemical reactions are observed with the naked eye. There are specific color changes that indicate the presence of a particular drug.

Question 13

What tests did you find to help you determine the drugs?

Answer 13

The marquis and the mandelin tests were useful in my final conclusion on the powder’s components.

Question 14

which of the two determined drugs did you test with the marquis test?

Answer 14

Both.
Diphenhydramine hcl which turned an instantly bright yellow.

Aspirin changed to brownish-red.

Question 15

and what were the results for the Mandelin test?

Answer 15

The aspirin turned brownish-red.

Question 16

what color change did powder reveal when tested with marq. and mand?

Answer 16

with the marquis it changed instantly to a bright yellow and with mandelins i noted instant black color.

Question 17

so the aspirin turned brown-red for both marquis and mendelin?

Answer 17

yes.

Question 18

what do these chemical tests detect?

Answer 18

they presumptively identifies alkaloids as well as other compounds

Question 19

what are alkaloids?

Answer 19

they are a class of naturally occurring organic nitrogen-containing bases. Many controlled substances are alkaloids.

Question 20

What was the last test you conducted on the powder?

Answer 20

I performed an acid-base extraction using a separatory funnel. then i analyzed the extracted sample using GCMS.

Question 21

can you explain the steps of how the negative control was prepared?

Answer 21

First, the negative control was prepared in a separatory funnel. 5ml of 0.2M sulfuric acid and 10 ml of chloroform was added, shaken. The chloroform layer was let out of the funnel. This step was done 3x. The pH was made basic by adding sodium hydroxide. 3ml of chloroform was added into the funnel, shaken, the pressure was released, and chloroform was drained into filter paper over a beaker. two more times 3ml of chloro. was added and drained into the beaker. The beaker was set up on a hot plate to evaporate to around 0.5ml, a very small portion. Lastly, around 2ml of 1.0M methanol was added to the evaporated beaker and mixed with a pipette. This was transferred to a GC vial for analysis.

Question 22

How was the powder analyzed?

Answer 22

A small amount of sample was added using the back of a toothpick into a separatory funnel. Similar to the negative control, the acid was added to the funnel. The powder dissolved in the acid. Next, 10ml chloroform was added. The funnel was shaken and the pressure was released. The chlorof. which is the bottom layer, was drained into a waste beaker. 10ml of chloroform was added and drained twice more.

Next, the pH of the aqueous layer in the funnel was checked and was at 13. No sodium hydroxide was added because it was at the desired basic pH.

Lastly, the same steps were taken as the negative control. 3ml of chloroform was added. Funnel was shaken, and pressure released, and chloroform layer on the bottom was released into a filter paper over a clean beaker. This was done twice more, for a total of three times. The beaker of extract was evaporated in the same manner and transferred with methanol to a gc vial.

The extract was run through the GC-MS.

Question 23

Why did you redo the extraction?

Answer 23

There were skewed results with the first extraction. There was not enough sample present in the extraction, so the second time i added more powder and the spectra came out accordingly.

Question 24

what extraction principle did you follow?

Answer 24

acid-base extraction in which a sample in put into acidic aqueous liquid, in this case hydro sulfuric acid, or H2SO4. The liquid is then washed with organic solvent, in this case chloroform. This step removes neutral and acidic drugs from the aqueous layer. Then a base is added to push the pH higher to around 11-13. Sodium hydroxide is the base used in this extract. The organic solvent was used to extract the strongly basic drug from the very basic aqueous layer.

Question 25

what does the marquis test test for?

Answer 25

in literature, it is referenced that it tests for aromatic compounds which consist entirely of C, H, and N. As the ratio of these three elements increases, it gives rise to the change of colors through green to orange to red.

Question 26

what does the Mandelin’s test for?

Answer 26

literature references that brown and black colored changes at room temperature indicate potent reducing powder which occurs when adjacent carbon atoms in a ring bear a hydroxyl, or -OH, group.

Question 27

what is the FRN number located at the top right of the case notes?

Answer 27

It stands for forensic report number.

Question 28

what were the gc-ms results outcomes?

Answer 28

the direct analysis and extracted sample analysis both showed a major peak at retention time of 7 minutes indicating the presence of sample in the extraction.

The standard diphendramine hcl in the lab data base showed a major peak at 7 minutes which allowed for conclusion that diphenhydramine hcl was a component in the powder.

Question 29

what conclusions did you make with the ftir spectra?

Answer 29

the standard, aspirin, showed nearly identical peaks to the powdered sample. This allowed to conclusion on aspirin also present in the powder.