07 February 2011
Dept of Chemistry by Farhana
Doing practical in DOC, for sure it is 100% research-oriented. Every branch in Malaysia has at least 8 labs. But in Penang, only four will carry out food-related analysis (Food Lab, Mycotoxin Lab, IKTD Lab, &
Food Section provides three main services;
1) Additives & contaminants (major)
2) Standards & specifications (nutrition labeling)
3) Pesticide residue.
But for now, pesticide analysis already is in charge of Mycotoxin Lab. Halal analysis not offered here. If there are any Halal-related cases, it will be sent to HQ (Petaling Jaya) for DNA analysis. Some urgent
cases like foreign matters analysis (especially those involve pest like cockroach) or melamine cases also will be referred straight to HQ as it equipped with better technique and equipment.
These are brief list of my activities in DOC through January
(Week1 – Week4):
1) Learn safety rules & equipment
I have been taught to choose suitable PPE (Personal Protective Equipment) according to experiment. For common analysis, we can use latex gloves and mask. But when handling hazardous chemical, face
shield, glass/goggle and respirator are applied. Nitrile gloves and carbon-free mask even recommended. Lab workers also must know how to operate and check efficiency of emergency response equipment (eye-wash
station, shower, fire blanket).
2) Learn basic handling of apparatus & equipment
Although it looks simple, but not all peoples know how to use common apparatus in correct way, include me. Sometimes due to inadequate equipment, we don’t have the opportunity to handle the apparatus in
lab session. So, I do recommend our faculty to do basic lab skill workshop (practically) for our junior (maybe senior also…).
3) Compile most of test method manual used in DOC
For DOC, each method is continually validated and improved. Modification will be done by HQ if there is any better analytical method.
4) Be involved in handling of food sample sent by client
• Important client: Health Department, army, private company
• Food sample registered and described in sample forms and worksheet
• Case determined formal/informal or urgent/TUL/common
• Unused sample stored in storage room (in cabinet/oven/freezer/ chiller)
• After analysis, calculation and result compiled with worksheet
• Status of case determined (compiled or not)
• Duplicate test done for non-compiled case
• Sample used disposed and result sent to client (For army cases, result:30 days after sample sent, other cases: 50 days)
5) Analysis of heavy metal by using AAS
This is my major task in Food lab, but still focusing on dried form sample. Previously, the analysis is done by Mr.Ramli, but he just transferred to HQ. Most food sample is tested for presence of Pb and Cd by using Avanta software. Examples of common sample received are sardines in tomato sauce, milk powder, MSG, dried squid, and energy drink.
From 15 samples, only one (dried seaweed) is not complied in term of its cadmium level. Duplicate test must be carried out in this case. For mercury analysis in food, mercury analyzer is used as alternative. AAS only used for non-food analysis of mercury. Until now, Food Lab has remaining 52 samples to be analyzed with AAS.
6) Analysis of foreign matter by using FTIR
The sample is tamarind paste, which contaminated with plastic and hair. By using OMNIC software, absorbance curve are obtained (FTIR is the simplest equipment I ever handled). After ATR and baseline
correction done, result compared with library database. The plastic detected as polyethylene and polypropylene. But the hair shown result for wheat gluten flour. So, it was sent to Criminalistic lab for
better analysis (also to check whether it is animal or human hair)
7) Research Project : Determination of Boric Acid in Noodles by using UV- spectrophotometer
For this project, alcoholic turmeric extract will be used as indicator in qualitative test. If cherry-red color formed, the sample can be preceded to quantitative test by using UV-spectrophotometer. But I
still stuck in the calibration of Boron standard solution. Personally, I do think it such a difficult project. I heard that previous practical student also got this project, give up and change her research last minute (she even crying, which make me want to do it too … T-T). Dealing with extra-hazardous (everything is highly
concentrated), plus highly unstable chemicals, we already taken maximum safety precaution. Yet the result of standard graph remained fluctuated (I already repeated it 7X). I will continue trying, and maybe request another research project at the same time as alternative. But handling 500ml concentrated H2SO4 by my own in preparation of Carmine reagent is such a great experience (shaking so much, but feel like newly-born after do that...hehe).
My Plan for February activities
Continue research project of boric acid
Planning for alternative research project (any suggestion?)
Carry out wet sample analysis wit AAS
Learn operation of GC (determination of % alcohol in wine, rum, gin, & vodka)