2008 Analysis of the Geometry of Drilled Holes in Demolition ...

leaching properties and can be used as an alternative to the commercially used
chlorine bleaches.
Extracts from the fruits were obtained through the use of a Soxhlet
Apparatus and a rotary evaporator. For each fruit extract, two concentrations of
solutions (50% and 100%) that were tested on numbered pieces of white cotton
cloth that were stained with either chocolate or soy sauce. All solutions were also
tested for shelf life. A separate group of stained cloths were also tested with
commercial bleach for comparison. Colors of the cloth stains were noted before
and after the bleaching.
Results show that kamias bleach is more effective on soy sauce stains and
chocolate stains than the balimbing bleach, though both were not able to fully
remove the stains like the commercial bleach did, possibly due to low
concentrations of oxalic acid. The fruit extracts were also observed to have left
green marks on the pieces of cloth used, which could possibly have been caused
by the presence of unknown substances. The extracts were also observed to
degrade within a week’s time of exposure to air.
The use of extracts form Kamias and Balimbing as a feasible alternative to
commercial bleaches is still feasible, but an improved extraction process or
isolation of the oxalic acid in the extracts may be done to ascertain that the green
marks did not come from the oxalic acid, and to prolong the shelf life of the
bleach extracts.
#67
Heavy metal analysis of Manganese and zinc in virgin coconut
oil through flame atomic absorption spectroscopy
Precious Ann L Nepomuceno, Marianne Therese Amelia P Padilla, Abbi D Santos
ABSTRACT
Virgin coconut oil (VCO) is produced from fresh coconut meat. Unlike
regular coconut oil, it does not undergo chemical refining processes. Because of
its many uses, it is economically significant. However, VCO can also be prone to
oxidation. The presence of heavy metals in the oil may affect its oxidative ability.
Manganese in VCO mat decrease oxidative stability and shelf life, while zinc, an
antioxidant, does otherwise.
The study deals with the verification and quantification of the presence of
the heavy metals manganese and zinc in commercially produced virgin coconut oil.
The results of this project can be used as a basis for setting up standards for the
concentrations of manganese and zinc for commercial brands of VCO. It also
provides data for the possible expansion of the Philippine National Standard for
VCO, which currently only includes arsenic, lead, copper and iron in its of heavy
metals in VCO.
Analysis was done using Flame Atomic absorption spectroscopy (FAAS). A
calibration curve was generated using standard solutions of Mn and Zn. Four