Do you know how to prepare the solutions or how much i need weigh each of parben

Question

Do you know how to prepare the solutions or how much i need weigh each of parbens

The unknown sample is containing methyl-paraben, ethyl-paraben and propyl-paraben, each at a concentration in the range 25-75mg/L.

prepare two sets of solutions so can compare the use of a normal calibration procedure with the standard addition method. The set of calibration standards should be multistandards; in other words, each solution contains all three analytes. Prepare a solution containing all three paraben species at a concentration suitable for use in the SA method then use this with a portion of unknown to prepare a set of SA solutions.

Explanation / Answer

Weigh 40.0 mg each of methyl, ethyl, propyl, and butyl parabens into a 100 mL volumetric flask. Add approximately 50 mL 70% ethanol to dissolve, This is considered to be stock solution

Combine 0.0, 0.25, 0.50 and 1.0 mL of each stock standard into 50 mL volumetric flasks and dilute to volume with 70% ethanol. These dilutions prepare standard solutions at the following concentrations:

So thus we get 4 sets of solution where ecah set has different combination of methyl, ethyl and propyl parabens

Now unknown set can be used after we finish calibraing with thse 4 set of standards

Please check these links which might help you better:

http://www.fsis.usda.gov/wps/wcm/connect/80689fb4-dbac-4f22-9375-96d5e2b811f4/CLG_BSP_01.pdf?MOD=AJPERES

https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CB0QFjAA&url=http%3A%2F%2Fcfi.insa-rouen.fr%2Fenseignements%2Flaboenseignements%2Fchimieanalytique%2Fparaben-english.pdf&ei=Ra7-VP-5OY6luQTN44HgDw&usg=AFQjCNHPcDrGs5V-OlulkpxvqRONP7KMQA&bvm=bv.87920726,d.c2E

Related Questions

Navigate

• Browse (All)
• Browse D
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.