Discrimination and authentication of lard blending with palm oil in cosmetic soap formulations

Background: The employment of Fourier transforms infrared (FT-IR) spectroscopy combined with chemometrics for determination and quantification of lard in a binary blend with palm oil in a cosmetic soap formulations. Objective: To determine and quantify lard as an adulterant in a binary blend with palm oil in a cosmetic soap formulations by FT-IR and multivariate analysis. Methods: Fatty acids in lard, palm oil and binary blends were extracted via liquid–liquid extraction and were subjected to FTIR spectrometry, combined with principal component analysis (PCA) and discriminant analysis (DA) for the classification of lard in cosmetic soap formulations via two DA models: Model A (percentage of lard in cosmetic soap) and Model B (porcine and non-porcine cosmetic soap). Linear regression (MLR), partial least square regression (PLS-R) and principal components regression (PCR) were used to assess the degree of adulteration of lard in the cosmetic soap. Findings: The FTIR spectrum of palm oil slightly differed from that of lard at the wavenumber range of 1453 cm−1 and 1415 cm−1 in palm oil and lard, respectively, indicating the bending vibrations of CH2 and CH3 aliphatic groups and OH carboxyl group respectively. Both of the DA models could accurately classify 100% of cosmetic soap formulations. Nevertheless, less than 100% of verification value was obtained when it was further used to predict the unknown cosmetic soap sample suspected of containing lard or a different percentage of lard. The PCA for Model A and Model B explained a similar cumulative variability (CV) of 92.86% for the whole dataset. MLR and PCR showed the highest determination coefficient (R2) of 0.996, and the lowest relative standard error (RSE) and mean square error (MSE), indicating that both regression models were effective in quantifying the lard adulterant in cosmetic soap. Conclusion: FTIR spectroscopy coupled with chemometrics with DA, PCA and MLR or PCR can be used to analyse the presence of lard and quantify its percentage in cosmetic soap formulation

Removal of Phosphate by Paper Mill Sludge: Adsorption Isotherm and Kinetic Study

Phosphate ions have been removed from aqueous solution by paper mill sludge. The influences of experimental conditions such as pH, amount of adsorbent, initial concentration of phosphate, adsorption isotherm and adsorption kinetics of paper mill sludge were studied. The adsorption of phosphate was more efficient in the basic pH region (pH 12). Pseudo second-order model fits better than the pseudo first-order model for adsorption kinetic data and indicates the adsorption process is based on chemisorptions. The calculated activation energy (Ea) is 37.01 J/mol which further suggests that the sorption of phosphate by paper mill sludge was based on chemical adsorption. Consequently, the equilibrium isotherm data were fitted well to Langmuir isotherm with maximum adsorption capacity of 12.65 mg/g. From the study, it showed that paper mill sludge has the potential to be utilized as a cost effective and high capability adsorbent for removal of phosphate from aqueous solutions

Engaging students in a critical style of reflective practice through formative assessment

Higher education teaching and learning employ different approaches and techniques to empower students' learning experiences. The critical style of reflective practice in higher education is significant in preparing students for professional development, research competencies and deep learning (Glass, 2015). The word reflection has diverse meanings, described as the continuous and active engagement towards any form of knowledge resources with the employment of critical thinking (Dewey, 1983). Schön (1983) emphasised reflection activity as a method of re-evaluating experiences in different forms comprising individual comprehension of self and others. The critical style of reflective practice requires continuous efforts, attempts, and complex thought processing of unstructured ideas from various resources (Moon, 1999). Reflection also includes experiences and the development of insights, which enable the active functioning of cognitive and affective elements (Boud et al.,1985). Therefore, the growth of reflective practice needs active engagement and thinking to arouse individual performance in reflection (Boud, Keogh & Walker, 1996)

Process conditions for the manufacture of highly micro-mesoporous eco-friendly activated carbon from artocarpus integer bio-waste by steam activation

In this paper, for the first time, we report the process conditions to obtain highly micro-mesoporous eco-friendly activated carbon (Eco-AC) from Artocarpus integer bio-waste by steam activation. The proposed novel material provides a green alternative to existing chemically activated bio-wastes for the preparation of highly micro-mesoporous activated carbon. The influences of pyrolysis temperature and duration followed by steam-gasification temperature and duration on the pore structure and yield of Eco-ACs were explored in this study. The prepared Eco-ACs had been characterized by N2 adsorption-desorption analysis and FESEM. Based on our experimental results, the optimum technology conditions for preparing highly micro-mesoporous Eco-AC are: pyrolysis temperature, 700 °C; pyrolysis duration, 60 min; steam-gasification temperature, 750 °C; and steam-gasification duration, 60 min. The optimal Eco-AC has a BET surface area of 852.63 m2/g, Langmuir surface area of 964.79 m2/g, t-plot micropore surface area of 506.03 m2/g, t-plot mesopore surface area of 346.60 m2/g, total pore volume of 0.632 cm3/g, BET average pore diameter of 2.967 nm and BJH average pore diameter of 5.489 nm with a reasonable yield, 33.5%, making it a promising economical and eco-friendly carbon material for use in environmental separation technologies and water treatment

Modified APHA closed-tube reflux colorimetric method for TOC determination in water and wastewater

The analysis of total organic carbon (TOC) by the American Public Health Association (APHA) closed-tube reflux colorimetric method requires potassium dichromate (K2Cr2O7), silver sulfate (AgSO4), and mercury (HgSO4) sulfate in addition to large volumes of both reagents and samples. The method relies on the release of oxygen from dichromate on heating which is consumed by carbon associated with organic compounds. The method risks environmental pollution by discharging large amounts of chromium (VI) and silver and mercury sulfates. The present method used potassium monochromate (K2CrO4) to generate the K2Cr2O7 on demand in the first phase. In addition, miniaturizing the procedure to semi microanalysis decreased the consumption of reagents and samples. In the second phase, mercury sulfate was eliminated as part of the digestion mixture through the introduction of sodium bismuthate (NaBiO3) for the removal of chlorides from the sample. The modified method, the potassium monochromate closed-tube colorimetry with sodium bismuthate chloride removal (KMCC-Bi), generates the potassium dichromate on demand and eliminates mercury sulfate. The semi microanalysis procedure leads to a 60% reduction in sample volume and ≈ 33.33 and 60% reduction in monochromate and silver sulfate consumption respectively. The LOD and LOQ were 10.17 and 33.90 mg L−1 for APHA, and 4.95 and 16.95 mg L−1 for KMCC-Bi. Recovery was between 83 to 98% APHA and 92 to 104% KMCC-Bi, while the RSD (%) ranged between 0.8 to 5.0% APHA and 0.00 to 0.62% KMCC-Bi. The method was applied for the UV-Vis spectrometry determination of COD in water and wastewater. Statistics was done by MINITAB 17 or MS Excel 2016

A simple method for chromium speciation analysis in contaminated water using APDC and a pre-heated glass tube followed by HPLC-PDA

In this study, a simple sample preparation method was developed for the determination of tri-and hexavalent chromium in water samples. It utilizes a pre-heated customized glass tube (CGT), to supply the heat energy required for the reaction of Cr(III) with ammonium pyrrolidinedithiocarbamate (APDC). The products of the Cr complexes, tris(1-pyrrolidinecarbodithioato)chromium(III) and bis(1-pyrrolidinecarbodithioato)[1-pyrrolidinecarbodithio(thioperoxoato)]chromium(III) were chromatographed with Shimadzu LC-20AT and Zobax Eclipse C18 (150 mm × 4.6 mm, 5 µm) column using ACN: Water, (7:3, v/v) as the mobile phase. The concentration of Cr(III) ranged from 0.06 mgL−1 to 0.09 mgL−1 and that of Cr(VI) was between 0.02 mg L−1 to 0.04 mgL−1 in the samples. Percentage recoveries from spiked real samples were between 87% (tap water) to 110% (wastewater) for Cr(III) and 92% (pond water) to 117% (tap water) for Cr(VI). The limits of detection (LODs) were 0.0029 mg L−1 and 0.0014 mg/L−1 for Cr(III) Cr(VI) respectively. While the limits of quantitation (LOQs), were 0.0098 mg L−1 and 0.0047 mg L−1 for Cr(III) and Cr(VI) respectively. Method precision (RSD (%)) was 3.3% and 3.5% for Cr(III) and Cr(VI) respectively. The developed method was applied for the speciation analysis of chromium in drinking water, tap water, wastewater, river water, and pond water samples. Our findings proved the method is simple and inexpensive. The method was validated by the analysis of a certified reference material (CRM) SLRS-4. The percentage recovery and RSD(%) from the spiked CRM were 91% and 115% and 0.32% and 1.4% for Cr(III) and Cr(VI) respectively

Determination of polar aromatic amines using newly synthesized sol–gel titanium (IV) butoxide cyanopropyltriethoxysilane

A solid phase extraction (SPE) method has been developed using a newly synthesized titanium (IV) butoxide-cyanopropyltriethoxysilane (Ti-CNPrTEOS) sorbent for polar selective extraction of aromatic amines in river water sample. The effect of different parameters on the extraction recovery was studied using the SPE method. The applicability of the sorbents for the extraction of polar aromatic amines by the SPE was extensively studied and evaluated as a function of pH, conditioning solvent, sample loading volume, elution solvent and elution solvent volume. The optimum experimental conditions were sample at pH 7, dichloromethane as conditioning solvent, 10 mL sample loading volume and 5 mL of acetonitrile as the eluting solvent. Under the optimum conditions, the limit of detection (LOD) and limit of quantification (LOQ) for solid phase extraction using Ti-CNPrTEOS SPE sorbent (0.01-0.2; 0.03-0.61 µg L(-1)) were lower compared with those achieved using Si-CN SPE sorbent (0.25-1.50; 1.96-3.59 µg L(-1)) and C18 SPE sorbent (0.37-0.98; 1.87-2.87 µg L(-1)) with higher selectivity towards the extraction of polar aromatic amines. The optimized procedure was successfully applied for the solid phase extraction method of selected aromatic amines in river water, waste water and tap water samples prior to the gas chromatography-flame ionization detector separation

Preparation and characterization of titania-cyanopropyltriethoxysilane sorbent for the extraction of polar aromatic amines

A new titanium(IV) butoxide-cyanopropyltriethoxysilane (Ti-CNPrTEOS) hybrid material was successfully synthesized for the use as sorbent for the extraction of polar aromatic amines. The sorbent was synthesized by hydrolysis and condensation of titanium(IV) butoxide and cyanopropyltriethoxysilane with the presence of hydrochloric acid as catalyst via sol–gel method. Several factors influencing the synthesized sorbent such as solvent selection, mol of water content, ratio of titanium(IV) butoxide and cyanopropyltriethoxysilane and aging temperature were investigated and optimized. The sorbents were characterized by fourier transform-infrared, field-emission scanning electron microscopy-energy, CHN elemental analysis and thermogravimetric analysis. The applicability of the sorbents for the extraction of polar aromatic amines by the batch sorption method was extensively studied and evaluated. Under the optimum synthesis conditions (tetrahydrofuran as solvent, 1.2 M of hydrochloric acid catalyst, 4 mol of water content with ratio of titanium(IV) butoxide and cyanopropylteriethoxysilane of 1:1 and aging temperature of 60 C), the extraction showed high recovery towards the extraction of polar aromatic amines. The synthesized sorbent was successfully applied for the extraction of selected aromatic amines via batch sorption method in waste water samples prior to the gas chromatography-flame ionization detector separation. The synthesized sol–gel Ti-CNPrTEOS sorbent demonstrated the potential as an alternative extraction sorbent with higher selectivity towards polar aromatic amines

Effect of Mobile Phase pH on the Electrospray Ionization Efficiency and Qualitative Analysis of Pharmaceuticals in ESI + LC-MS/MS

The effect of mobile phase pH on positive ionization process and retention time of nine pharmaceuticals on ultra-performance liquid chromatography-electrospray-tandem mass spectrometry (LC-MS/MS) was discussed. The effective use of high and low mobile phase pH in LC-MS/MS qualitative analyses method was also evaluated by comparing the instrument detection limit, quantification limit, precision, linearity and signal to noise (S/N) under low and high mobile phase pH. In this work, six mobile phase pH that ranged between pH 2 and pH 10 were used to evaluate the effect of the mobile phase pH changes on the ionization process in electrospray ionization. Results revealed that high mobile phase pH ionized more pharmaceuticals molecules and gave a higher signal than low mobile phase pH in positive ionization mode. The results proved that ammonium ion was better as a proton donor in high pH mobile phase than the hydronium ion in acidic mobile phase. The results revealed that the qualitative LC-MS/MS analyses method by using high mobile phase pH has better performance for most analytes in terms of sensitivity, precision, linearity and S/N than the low mobile phase pH. © 2019 The Author(s). Published by Oxford University Press. All rights reserved

Metabolomics approach using LC-Orbitrap high resolution mass spectrometry and chemometrics for authentication of beef meats from different origins in Indonesia

Beef is one of the favourite meats consumed by people worldwide due to its high nutrition value needed by human development. It is highly susceptible for the adulteration practice by substituting beef with lower price meats by unethical meat traders due to the economic reasons. Therefore, the authenticity of beef meat (BM) is important because it is also related to halal status of meat which is required for certain religions. This research aimed to differentiate metabolites of BM from different origins using liquid chromatography-high resolution mass spectrometry (LC-HRMS) combined with chemometrics for the authentication purposes. Various metabolites mostly amino acids and lipids could be detected using methanol extraction. Principal component analysis (PCA), partial least square-discriminant analysis (PLS-DA) and sparse PLS-DA were successfully used to discriminate BMs from different origins. Fifty potential metabolite markers which are important for discrimination have been identified using variable importance projection (VIP) value extracted from PLS-DA analysis. Metabolites of (4S)-4-{[(9Z)-3-Hydroxy-9-hexadecenoyl] oxy}-4-(trimethylammonio)butanoate, N,N-Diisopropylethylamine (DIPEA), D-sphingosine, (2E,4Z)-N-Isobutyl- 2,4-octadecadienamide, 1-(14-methylhexadecanoyl)pyrrolidine, linoleic acid, 12-HAS, dodecylamine1, myristamide, and tributyl phosphate had high responsibility in discriminating BMs from different origins (VIP value > 2.0). It can be concluded that LC-HRMS based untargeted metabolomics combined with chemometrics could be used for authentication of BMs from different regions