Tongkat Ali (Eurycoma longifolia) is one of the most popular tropical herbal plants as it is believed to enhance virility and sexual prowess. This study looked examined chromatographic fingerprint of Tongkat Ali roots and its products generated using online solid phase-extraction liquid chromatography (SPE-LC) combined with chemometric approaches. The aim was to determine its quality. Pressurised liquid extraction (PLE) technique was used prior to online SPE-LC using polystyrene divinyl benzene (PSDVB) and C18 columns. Seventeen Tongkat Ali roots and 10 products (capsules) were analysed. Chromatographic dataset was subjected to chemometric techniques, namely cluster analysis (CA), discriminant analysis (DA) and principal component analysis (PCA) using 37 selected peaks. The samples were grouped into three clusters based on their quality. The PCA resulted in 11 latent factors describing 90.8% of the whole variance. Pattern matching analysis showed no significant difference (p>0.05) between the roots and products within the same CA grouping. The findings showed the combination of chromatographic fingerprint and chemometric techniques provided comprehensive evaluation for efficient quality control of Tongkat Ali formulation.
Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) has been recognised as an effective technique to analyse car paint. This study was conducted to assess the combination of Py-GC-MS and chemometric techniques to classify car paint primer, the inner layer of car paint system. Fifty car paint primer samples from various manufacturers were analysed using Py-GC-MS, and data set of identified pyrolysis products was subjected to principal component analysis (PCA) and discriminant analysis (DA). The PCA rendered 16 principal components with 86.33% of the total variance. The DA was useful to classify the car paint primer samples according to their types (1k and 2k primer) with 100% correct classification in the test set for all three modes (standard, stepwise forward and stepwise backward). Three compounds, indolizine, 1,3-benzenedicarbonitrile and p-terphenyl, were the most significant compounds in discriminating the car paint primer samples.
Nanofiltration membranes technology commonly used for wastewater treatment especially
wastewater containing charged and/or uncharged species. Commonly, textile wastewater
possesses high chemical oxygen demand (COD) and non-biodegradable compounds such as
pigments and dyes which lead to environmental hazard and serious health problem. Therefore, the
objective of this study was to investigate the effects of hydrophilic surfactant on the preparation and
performance of Active Nanofiltration (ANF) membrane. The polymeric ANF membranes were
prepared via dry/wet phase inversion technique by immersion precipitation process. The
Cetyletrimethylammonium bromide (CTAB) as cationic surfactant was added in casting solution at
concentrations from 0 to 2.5 wt%. The synthesized membrane performance was evaluated in terms
of pure water permeation (PWP) and dye rejection. The experimental data showed that the
membrane demonstrated good increment of PWP ranging from 0.27 to 10.28 L/m2
h at applied
pressure from 100 to 500kPa, respectively. Meanwhile, the ANF membranes achieved high
removal of Methyl Blue and Reactive Black 5 dye up to 99.5% and 91.6%, respectively.
Water pollution has become a growing threat to human society and natural ecosystem in recent decades, increasing the need to better understand the variabilities of pollutants within aquatic systems. This study presents the application of two chemometric techniques, namely, cluster analysis (CA) and principal component analysis (PCA). This is to classify and identify the water quality variables into groups of similarities or dissimilarities and to determine their significance. Six stations along Kinta River, Perak, were monitored for 30 physical and chemical parameters during the period of 1997-2006. Using CA, the 30 physical and chemical parameters were classified into 4 clusters; PCA was applied to the datasets and resulted in 10 varifactors with a total variance of 78.06%. The varifactors obtained indicated the significance of each of the variables to the pollution of Kinta River.
The water chemistry of selected rivers in Kota Marudu, Sabah was studied based on the major ion chemistry and its suitability for drinking and irrigation purposes. Ten sampling stations were selected and water samples were collected from each station to assess its chemical properties. The physico-chemical variables including temperature, electrical conductivity (EC), total dissolved solids (TDS), salinity, dissolved oxygen (DO), pH, turbidity, ammoniacal-nitrogen (NH3-N), biological oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solid (TSS) were measured. The cations (K, Mg, Ca, Na) were analyzed by ICP-MS. Most of the variables were within the drinking water quality standards stipulated by the World Health Organization (WHO) and the Ministry of Health (MOH), Malaysia except for turbidity. Sodium adsorption ratio (SAR) and salinity hazard were calculated to identify the suitability of the water as irrigation water. The Wilcox diagram classifies that only 10% of samples are not suitable for the purpose of irrigation. The overall results showed that most of the rivers in Kota Marudu are still in a clean condition and suitable for drinking and irrigation purposes except for Sumbilingan River, which is considered as slightly polluted. The results are supported by the hierarchical cluster analysis as the stations were grouped into two groups; low and high pollution intensities. This preliminary result can update the baseline data of selected water quality parameters in the Kota Marudu and could serve as tool for assisting relevant government bodies in regulating the water resources policies in the future.
The purpose of this study is to determine spatial pattern recognition of school performance based on
children’s anthropometric and motor skills component. This study involved 94 primary schools with a
total 2237 male students aged 7.30±0.28 years in Pahang, Malaysia. The parameters of anthropometric
(weight and height) and motor component included lower muscular power (standing broad jump),
flexibility (sit and reach), coordination (hand wall toss) and speed (20 meter run) were selected. Cluster
Analysis (CA) and Discriminant Analysis (DA) under Multivariate Method and technique of Kriging
Interpolation in Geographic Interpolation Software (GIS) were used. CA revealed two clusters of school
performance. There are a total 34 high performance schools (HPS) and 60 low performance schools
(LPS). Then, the assigned groups were treated as independent variable (IV) while anthropometric and
motor parameters were treated as dependent variable (DV) in DA. Standard mode of DA obtained
95.74% correctness of classification matrix with three discriminated variables (height, standing broad
jump and 20 meter run) out of six variables. Meanwhile, forward and backward stepwise mode of DA
discriminated only one (standing broad jump) out of six variables with 96.81% of classification
correctness. The map output of Kriging interpolation has shown graphically the pattern of discriminated
variables that greatly influence school performance. It exposed the ability of children motor skills
development in particular region is higher than another region.
The hydrology hydraulic model is established to assess environmental information on hydrology which
can be used to investigate causes of various environmental problems at the river and natural lake
catchment. This study reports on sediment concentrations at a river using a gravimetric method to
investigate the hydrology system at a lake catchment. The measurement was carried out at the
upstream, midstream, and downstream stations on the river in normal, rainy and post-rainy seasons.
The stations are located along the Chini River, which are connected to a catchment lake (located at
latitude 3°26’36.41”E-3°27’03.26”E and longitude 102°54’31.94”N-102°53’35.49”N). From the
measurements, it is estimated that on average 787.621 tonne/km2 of sediment is transferred into the
natural lake via Chini River annually. The correlation of statistical analysis between the sediment load
and discharge study was very significant (R2 = 0.980). There is a linear relation between the area of
the catchment and sediment load of the connecting river as supported by other studies in Malaysia.
The outcome of the study suggests that the high sedimentation is due to land use activity, existence of
the dam at the downstream of Chini River that traps the sediment, reverse flow from the Pahang River
into Chini River and riverbank erosion factors. From this study, the sediment control steps are
suggested such as creating conservation partially at the lake catchment, modifying the dam system,
riverbank erosion control, and application of “Monkey Cheek” system. These sediment control steps
may help to clean up the high suspended sediment at the whole lake system area, hence solving and
mitigating the environmental problems in the natural lake catchment.
The purpose of this study was to analyze the relationship of airborne chemicals and the physical work environment risk element on the indoor air symptoms of nonindustrial workers.
To meet the current diversified health needs in workplaces, especially in nonindustrial workplaces in developing countries, an indoor air quality (IAQ) component of a participatory occupational safety and health survey should be included.