The Student Room Group

Formal lab report

Hiya guys can someone read my formal lab report draft and be able to give feedback as this is my first time ever writing a lab report.

Introduction*
A bag of white powder was seized from a pub in Sheffield. The bag was suspected to contain an illicit drug. Using advanced analytical techniques such as HPLC which works by injecting a sample of the drug into a Rheodyne valve which carries it into a stationary phase. The Rheodyne valve is used to ensure that the same volume is injected every time. The sample is then sent to a uv detector, and a chromatogram is produced of the unknown sample. GC-MS which works by the mobile phase being a gas and the stationary phase being a solid which is coated on the inside of the column. Before putting the sample into the mass spectrometer, it must be ionised first, this is done by firing electrons at the sample. After this the sample needs to be vapourised. The sample will be separated by mass and sent to a detector which will produce a spectrum of the unknown sample and FT-IR which is used because it is cost efficient and able to pick up atoms that were missed when the sample was run through the HPLC. was able to identify that this bag of white powder contained the illicit drug cocaine and the bulking agent benzocaine. The HPLC was used to identify and quantify the illicit drug. The GC-MS was used to further confirm the identity of the illicit drug. The FTIR was used to identify any bulking agents that the HPLC cannot identify as different molecules will absorb different wavelengths. In this case it identified that sorbitol was also found mixed in with the illicit drug. These 2 bulking agents were used as they are the same colour as cocaine and a similar composition. Benzocaine is used as a bulking agent as it is a numbing agent so has the same effects as cocaine. It is also cheaper and more accessible than cocaine.**
*
Materials and methods*
The HPLC manufacturer was Agilent with a Phenomenex Gemini C18 column. The mobile phase of this HPLC is a liquid. The column length is 250mm with a diameter of 4.6mm. During the HPLC two solutions were used sample A contains 10mm acetate in 80% and sample B contains 20% of acetonitrile. These were used as mobile phases. This HPLC has a wavelength of 254nm. The GC manufacturer was Agilent 6890A and the mass spectrometers manufacturer was Agilent 5975C. IT had an injector port temperature of 250 and a detector temperature of 270. The type of column used was a RTX5MS. The FT-IR spectrometer was manufactured by Perkin Elmer with a spectrum of 100. The main aims of this experiment were to identify the illicit drug present and what bulking agents were present. A final aim was to quantify the overall percentage purity of the suspected illicit drug. To conduct this experiment, you need to rinse the syringe with ultrapure deionised water and fill it with 0.4mL the unknown sample. Then inject this into the Rheodyne valve on the HPLC instrument. Push 0.2 of the sample and turn the valve down to inject. Repeat step 1 for the 3 standards provided which are cocaine, benzocaine and ketamine. Then analyse the chromatograms that have been collected and identify what substances are within the unknown sample. After this make up a set of calibration standards using 100ug/ml of the illicit drug in the sample which we know to be cocaine and deionised water. Then repeat step 1 for the calibration standards. Now you have the required information to plot a calibration curve to determine the concentration of cocaine in the sample.**
(edited 3 months ago)

Quick Reply

Latest

Trending

Trending