Is there a replacement for glacial acetic acid in determining peroxide value
Your school is not allowing use of glacial acetic acid, but you insist of using glacial acetic acid in determining peroxide value, you may use a solvent system, which consists of glacial acetic acid. For example, you can use 60% ($v/v$) glacial acetic acid in chloroform. I give that example because it is commercially available online at Reagents. If you are determining peroxide value of fats, this is an ideal solvent to dissolve fat and resultant solution is soluble in water. 

I'm suggesting this because there is a method recommended by International Fragrance Association (IFRA) in Belgium. Breifly, one of the IFRA analytical methods for determination of the peroxide value is described as follows:


  Transfer approx. $\pu{3.0 g}$ of the sample, accurately weighed, into a 250-mL Erlenmeyer flask with glass stopper. Add $\pu{50 mL}$ of the appropriate solvent mixture (glacial acetic acid : chloroform 3:2; glacial acetic acid : cyclohexane 3:2; glacial acetic acid : isooctane 3:2) and saturated potassium iodide solution, $\pu{1 mL}$, freshly prepared and allow to react for $\pu{60 ± 1 sec}$ and shaking thoroughly during this period. Then add water, $\pu{100 mL}$ and shake. Titrate with $\pu{0.01 mol/L}$ sodium thiosulfate solution, or $\pu{0.1 mol/L}$ sodium thiosulfate solution at higher usages, using $\pu{1 mL}$ starch solution or $\pu{0.1 g}$ of Thyodene indicator. The indicator should be added towards the end of the titration but while the pale straw color is still present. During titration shake until the blue color disappears. Carry out a blank titration under the same conditions. No more than $\pu{0.5 mL}$ of $\pu{0.01 mol/L}$ sodium thiosulfate solution should be consumed for this purpose.


Note: Use $\pu{0.1 mol/L}$ sodium thiosulfate solution when the expected peroxide values are $\gt \pu{20 mmol/L}$. Use $\pu{0.01 mol/L}$ sodium thiosulfate solution when the expected peroxide values are $\lt \pu{20 mmol/L}$.

Thyodene indicator is also commercially available in Fisher.