Friday, March 27, 2009

Report HPLC

Important criteria:

  • Plot standard curve of standard sample.
Result of standard sample (caffeine)

Link 1 (mediafire)
Link 2 (UsaUpload)
Link 3 (Filesend)

y-axis: Peak area
x-axis: Concentration of caffeine (ppm)

  • Find the linear equation from the above curve. y=mx+c.
  • From the equation, find the concentration for each sample, then multiply with the dilution faction of each sample. There should be 5 sample of different dilution.
Kalau dalam result korang ade byk peak, pilih peak yg retention time around plus minus 7 minute. Pastu carik concentration dari standard curve. Ni bukan true concentration. So korang kene multiply dgn dilution factor based on how many dilutions that you did for each sample.

Each sample should has the same concentration of caffeine since the sample came from the same solution (eg coke or nescafe).

  1. Observe sama ade korang nye concentration setiap sample tu same ke tak. Kalau xsame, maksudnye ade kesilapan time dilution.
  2. Next, compare dgn theoretical value of caffeine in coke/nescafe. setakat ni xde exact value. tp Dr Helal suruh check kat internet permissible content limit for coke and nescafa. Ape yg saye dpt jumpe:
  • Caffeine in coke: 200mg/liter
  • Caffeine in nescafe: 60mg/150ml
So,korang convert la ke ppm then compare ngan practical value. Sepatutnye kene same or kurang. Kalau lebih, maknenye ade error time dilution. Ape2 soalan or tambahan info leh ckp kat comment.

ps: Tak perlu buat standard deviation or percentage error. Just discuss point2 di atas. Seperti biase, precaution and how to decrease error if any.

Sekian -buzzingbee-


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