Abstract: A simple method for the simultaneous determination
of hippuric acid and benzoic acid in urine using reversed-phase high
performance liquid chromatography was described. Chromatography
was performed on a Nova-Pak C18 (3.9 x 150 mm) column with a
mobile phase of mixed solution methanol: water: acetic acid
(20:80:0.2) and UV detection at 254 nm. The calibration curve was
linear within concentration range at 0.125 to 6.0 mg/ml of hippuric
acid and benzoic acid. The recovery, accuracy and coefficient
variance of hippuric acid were 104.54%, 0.2% and 0.2% respectively
and for benzoic acid were 98.48%, 1.25% and 0.60% respectively.
The detection limit of this method was 0.01ng/l for hippuric acid and
0.06ng/l for benzoic acid. This method has been applied to the
analysis of urine samples from the suspected of toluene abuser or
glue sniffer among secondary school students at Johor Bahru.
Abstract: Nano MgO has been synthesized by hydration and
dehydration method by modifies the commercial MgO. The prepared
MgO had been investigated as a heterogeneous base catalyst for
transesterification process for biodiesel production using palm oil.
TGA, FT-IR and XRD results obtained from this study lie each other
and proved in the formation of nano MgO from decomposition of
Mg(OH)2. This study proved that the prepared nano MgO was a
better base transesterification catalyst compared to commercial MgO.
The nano MgO calcined at 600ºC had gives the highest conversion of
51.3% of palm oil to biodiesel.