ASSICNMENT $2(15\%)$

$$s$$cizas

LABORATORY QUALTY MANAGEMENT DAN VALDATION

OPTION $2$

Deneminaton of benzoic acid in soya sauce by HPLC$.$

Procodure:

Weigh $2\mathrm{.}0g$ sampie into $25mL.$ graduated tlask.

Add $10mL\mathrm{.}10s$ acetic acid:

Add $1mL$ intemal standard $($methy parsten $25mg)$

Add acetonitrile to the mark, titer sample with menterane titer

Calibrate HPLC with standard at $5$ levels between $16-280$ pom berzoic ackd standard

Inject $5L$ of each standard

$7.$ Inject $5$ uL of sample solution

The HPLC method for determination of berzoic acid was vabdated for analysis of differert types of soya sauce in the market. The range of benzoic acid is found to be in the range of $500-2500$ ppm$.$ The data obeained are as follows.

Table $3$: Concerveration of benzoic acid in different sample.

$\backslash$table$[[$Replicate No$.,$Sample A$,$Sample B$,$Sample C$,$Sample D$],[1,512,629,1378,2342],[2,509,640,140B,2410],[3,521,637,1396,2402],[4,529,621,1412,2398],[5,502,648,1422,],[6,516,630,,],[7,,642,,],[8,,638,,],[10,,645,,]]$

Write a lull report on this experiment and must include:

a$)$ Introduction

b$)$ Procedure

c$)$ Identifying uncertainty sources

d$)$ Determination of standard uncertainly due to precision based on data givon in Table $3.$

e$)$ Determination of uncertainty due to bias if certified value of CRM is $935$ ppm with standard deviation is $0\mathrm{.}56$ ppm at $95\%$ confidence lovel.

Detenmine of uncertainty associated with the Ris based on certifed value of CRM in $($e$).$

g$)$ Determination of corrbined standard uncertainty