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Recent Advances in Analysis of Pesticides in Food and Drink Samples Using LPME Techniques Coupled to GC-MS and LC-MS: a Review

Lawal A, Tan GH, Alsharif AM

J AOAC Int, 2016 Nov 01;99(6):1383-1394.
PMID: 27667201 DOI: 10.5740/jaoacint.16-0272

Food quality and food safety are major challenges affecting agricultural and industrial aspects of production. Many contaminants from different sources contaminate foods and drinks, leading to disastrous health problems like gene mutations and cancer. Previously, many different methods have been used for the analysis of these contaminants. Liquid-liquid extraction (LLE) has been the most well-known conventional technique used, but its limitations are its tediousness, time required, and the use of large quantities of toxic organic solvents. These limitations have led to the search for other, efficient techniques that are more environmentally friendly. Hence, this review highlights recent advances in liquid-phase (single-drop, hollow fiber, and dispersive liquid-liquid) microextraction procedures for food and drink analyses. Such modifications can be justified for solving limitations associated with the traditional LLE method. The objective of this review is to serve as a reference platform for providing effective management tools for solving problems of pollution, clean-up, and control of food quality and safety globally.
Diversity of Rickettsiae in Feeding and Questing Ticks Collected From a Malaysian Forest Reserve Area

Kho KL, Tan PE, Tay ST

J Med Entomol, 2019 02 25;56(2):547-552.
PMID: 30304529 DOI: 10.1093/jme/tjy168

High seropositivity to Rickettsia conorii and Rickettsia felis has been reported in Malaysian indigenous community living in settlements adjacent to forest areas. The current study was conducted to determine the type and distribution of rickettsiae in feeding and questing ticks that were collected from a forest reserve area at Kuala Lompat in Pahang, Malaysia. Using PCR assays targeting citrate synthase (gltA), outer membrane protein A (ompA) and B (ompB) genes, rickettsiae were detected from approximately one-third of 98 ticks (mainly Dermacentor and Haemaphysalis spp.) collected from the forest reserve. BLAST analysis reveals the predominance of Rickettsia sp. RF2125 in both feeding and questing ticks and Rickettsia sp. TCM1 in the questing ticks. Sequences exhibiting close genetic relationship with Rickettsia raoultii, Rickettsia tamurae, Rickettsia heilongjiangensis, and Rickettsia asiatica were also detected from the ticks. This study highlights the diversity of rickettsial species and potential tick vectors which may contribute to the high seropositivity observed among the local communities.
Confluent and reticulated papillomatosis: Case series of 3 patients from Kedah, Malaysia and literature review

Lee SW, Loo CH, Tan WC

Med J Malaysia, 2018 10;73(5):338-339.
PMID: 30350820 MyJurnal

Confluent and reticulated papillomatosis (CRP) was first described in 1927 by Gougerot and further characterised by Carteud.1 It is relatively rare, and the exact pathophysiology was not well known. Over the years, multiple treatment modalities were proposed. We report our experience with three cases of CRP which showed complete clearance with tetracycline group of antibiotics.
Fulltext An Intrinsic Mitochondrial Pathway Is Required for Phytic Acid-Chitosan-Iron Oxide Nanocomposite (Phy-CS-MNP) to Induce G₀/G₁ Cell Cycle Arrest and Apoptosis in the Human Colorectal Cancer (HT-29) Cell Line

Tan BL, Norhaizan ME, Chan LC

Pharmaceutics, 2018 Oct 23;10(4).
PMID: 30360519 DOI: 10.3390/pharmaceutics10040198

Magnetic iron oxide nanoparticles are among the most useful metal nanoparticles in biomedical applications. A previous study had confirmed that phytic acid-chitosan-iron oxide nanocomposite (Phy-CS-MNP) exhibited antiproliferative activity towards human colorectal cancer (HT-29) cells. Hence, in this work, we explored the in vitro cytotoxicity activity and mechanistic action of Phy-CS-MNP nanocomposite in modulating gene and protein expression profiles in HT-29 cell lines. Cell cycle arrest and apoptosis were evaluated by NovoCyte Flow Cytometer. The mRNA changes (cyclin-dependent kinase 4 (Cdk4), vascular endothelial growth factor A (VEGFA), c-Jun N-terminal kinase 1 (JNK1), inducible nitric oxide synthase (iNOS), and matrix metallopeptidase 9 (MMP9)) and protein expression (nuclear factor-kappa B (NF-κB) and cytochrome c) were assessed by quantitative real-time polymerase chain reaction (PCR) and western blotting, respectively. The data from our study demonstrated that treatment with Phy-CS-MNP nanocomposite triggered apoptosis and G₀/G₁ cell cycle arrest. The transcriptional activity of JNK1 and iNOS was upregulated after treatment with 90 μg/mL Phy-CS-MNP nanocomposite. Our results suggested that Phy-CS-MNP nanocomposite induced apoptosis and cell cycle arrest via an intrinsic mitochondrial pathway through modulation of Bax and Bcl-2 and the release of cytochrome c from the mitochondria into the cytosol.
Effect of ultrasound pre-treatment on adsorbent in dye adsorption compared with ultrasound simultaneous adsorption

Low SK, Tan MC, Chin NL

Ultrason Sonochem, 2018 Nov;48:64-70.
PMID: 30080587 DOI: 10.1016/j.ultsonch.2018.05.024

Ultrasound was applied simultaneously with adsorption process in most of the previous studies. However, this method is not practical to treat huge amounts of coloured wastewater effluent. In this study, the efficiency of ultrasound pre-treated peanut husk powder at different power levels (1.5-3.5 W) in dye adsorption with several conditions of initial dye concentration (20-100 mg/L), contact time (0.5-5 h), solution pH (2-8), and dosage (0.1-0.3 g) was studied and compared with ultrasound simultaneous adsorption process and the control. Adsorption efficiency of indirect ultrasound pre-treated peanut husk powder has increased 25.78%, 13.64% and 1.5% compared with the control, ultrasound simultaneous adsorption and direct ultrasound pre-treated sample respectively at 60 mg/L of initial dye concentration. Indirect ultrasound pre-treated sample at 3.5 W has achieved the highest adsorption efficiency of 89.96% at solution pH 8 and 94.83% at 0.3 g dose for 3 h. The surface feature and textural properties of samples were characterized by using scanning electron microscopy and surface characterization analyser. The result indicated that more porous structure was created on the ultrasound pre-treated sample at increasing power levels.
Social support, self-efficacy and their correlation among patients with Type 2 Diabetes Mellitus: A primary care perspective

Rashid AA, Zuhra H, Tan CE

Med J Malaysia, 2018 08;73(4):197-201.
PMID: 30121681 MyJurnal

INTRODUCTION: Social support and self-efficacy are factors that influence patients' health behaviour. However, the relationship between these two factors among patients with Type 2 Diabetes Mellitus (T2DM) has not been adequately explored. This study aims to report social support and selfefficacy of Malaysian T2DM patients, and their correlations.
METHODS: This cross-sectional questionnaire study involved 329 patients with T2DM who received their follow up at a public primary care clinic. Patients were selected via systematic random sampling. Patients self-completed locally adapted versions of the Medical Outcomes Study (MOS) Social Support Survey and Diabetic Management Self Efficacy Scale (DMSES). The scores of both tools were analysed to determine the association and correlation between social support and self-efficacy.
RESULTS: The mean score for overall social support was 72.7±21.40 score range (0-100). "Affectionate support" was rated the highest averaged mean score at 78.31±23.71 (score range: 0-100). The mean DMSES score was 147.6±35.5 (score range :0-200), of which "medications" subscale was rated the highest with averaged mean scores 9.07±1.67 (score range: 0-10). Overall social support and self-efficacy were found to be weakly correlated (r=0.197, p<0.001). However, all subscales of social support were moderately correlated with "medications" subscale of self-efficacy.
CONCLUSION: Social support is significantly associated with patients' self-efficacy in handling their own medications.
Mucoadhesive chitosan-coated nanostructured lipid carriers for oral delivery of amphotericin B

Ling Tan JS, Roberts CJ, Billa N

Pharm Dev Technol, 2019 Apr;24(4):504-512.
PMID: 30132723 DOI: 10.1080/10837450.2018.1515225

This study describes the properties of an amphotericin B-containing mucoadhesive nanostructured lipid carrier (NLC), with the intent to maximize uptake within the gastrointestinal tract. We have reported previously that lipid nanoparticles can significantly improve the oral bioavailability of amphotericin B (AmpB). On the other hand, the aggregation state of AmpB within the NLC has been ascribed to some of the side effects resulting from IV administration. In the undissolved state, AmpB (UAmpB) exhibited the safer monomeric conformation in contrast to AmpB in the dissolved state (DAmpB), which was aggregated. Chitosan-coated NLC (ChiAmpB NLC) presented a slightly slower AmpB release profile as compared to the uncoated formulation, achieving 26.1% release in 5 hours. Furthermore, the ChiAmpB NLC formulation appeared to prevent the expulsion of AmpB upon exposure to simulated gastrointestinal pH media, whereby up to 63.9% of AmpB was retained in the NLC compared to 56.1% in the uncoated formulation. The ChiAmpB NLC demonstrated mucoadhesive properties in pH 5.8 and 6.8. Thus, the ChiAmpB NLC formulation is well-primed for pharmacokinetic studies to investigate whether delayed gastrointestinal transit may be exploited to improve the systemic bioavailability of AmpB, whilst simultaneously addressing the side-effect concerns of AmpB.
Substrate Moisture Affects the Development of Megaselia scalaris (Diptera: Phoridae): An Implication of the Growth Circumstances of the Fly in Forensic Entomology

Ong SQ, Ahmad H, Tan EH

Environ Entomol, 2018 12 07;47(6):1582-1585.
PMID: 30165432 DOI: 10.1093/ee/nvy127

Megaselia scalaris (Loew) (Diptera: Phoridae) provides great evidential value in estimating the postmortem interval (PMI) compared with other dipterans due to its common occurrence on human corpses both indoors and in concealed environments. Studies have focused on the effect of temperature, larval diet, and photoperiod on the development of the species; however, knowledge of M. scalaris development at different moisture levels is insufficient. This study aimed to investigate the effects of substrate moisture on the larval development time, pupal recovery, pupal weight, adult emergence, and adult head width of M. scalaris. The larvae were reared in five replicates on substrates with six moisture levels ranging from 50 to 90%. Larvae and puparia were sampled daily, and the collection time, number, and weight were recorded, measured, and then compared using multivariate analysis of variance with a post hoc least significant difference test. Larvae developed most quickly (3.75 ± 0.04 d) at 50% substrate moisture; the larvae were able to survive in extremely wet substrates (90% moisture), but the development time was significantly longer (6.48 ± 0.19 d). Moisture greatly influenced the pupation rate and adult emergence but showed a weak effect on the pupae weight and adult head width. Due to the significance of moisture on the development of M. scalaris, PMI estimation using M. scalaris with cadavers of different moisture content must be carefully conducted to avoid inaccuracy.
Stability of Bioactive Compounds and Antioxidant Activities of Kenaf Seed Oil-in-Water Nanoemulsions under Different Storage Temperatures

Cheong AM, Tan CP, Nyam KL

J Food Sci, 2018 Oct;83(10):2457-2465.
PMID: 30178877 DOI: 10.1111/1750-3841.14332

Kenaf seed oil-in-water nanoemulsions (NANO) stabilized by sodium caseinate (SC), beta-cyclodextrin (β-CD), and Tween 20 (T20) have been optimized and shown to improve in vitro bioaccessibility and physicochemical stability in the previous study. The main objective of this study was to evaluate the stability of bioactive compounds and antioxidants in the NANO during storage at different temperatures (4 °C, 25 °C, and 40 °C). An evaluation of the antioxidant activities of each emulsifier showed that SC had good scavenging capability with 97.6% ABTS radical scavenging activity. Therefore, SC which was used as one of the main emulsifiers could further enhanced the antioxidant activity of NANO. At week 8 of storage, NANO that stored at 4 °C had maintained the best bioactive compounds stability and antioxidant activities with 90% retention of vitamin E and 65% retention of phytosterols. These results suggested that 4 °C would be the most suitable storage temperature for NANO containing naturally present vitamin E and phytosterols. From the accelerated storage results at 40 °C, NANO containing vitamin E and phytosterols had maintained half of its initial concentration until week 4 and week 2 of storage, which is equivalent to 16 weeks and 8 weeks of storage at room temperature, respectively.
PRACTICAL APPLICATION: The results of this study provide a better understanding on the stability of bioactive compounds and antioxidant activities in oil-in-water nanoemulsions that stabilized by similar ternary emulsifiers during storage at different temperatures. In addition, this study could be used as a predictive model to estimate the shelf life of bioactive compounds encapsulated in the form of nanoemulsions.
Effect of Gum Arabic, β-Cyclodextrin, and Sodium Caseinate as Encapsulating Agent on the Oxidative Stability and Bioactive Compounds of Spray-Dried Kenaf Seed Oil

Chew SC, Tan CP, Nyam KL

J Food Sci, 2018 Sep;83(9):2288-2294.
PMID: 30074623 DOI: 10.1111/1750-3841.14291

Kenaf seed oil is prone to undergo oxidation due to its high content of unsaturated fatty acids, thus microencapsulation stands as an alternative to protect kenaf seed oil from the adverse environment. This study primarily aimed to evaluate the oxidative stability of microencapsulated refined kenaf seed oil (MRKSO) by the use of gum arabic, β-cyclodextrin, and sodium caseinate as the wall materials by spray drying. Bulk refined kenaf seed oil (BRKSO) and MRKSO were kept at 65 °C for 24 days to evaluate its oxidative stability, changes of tocopherol and tocotrienol contents, phytosterol content, and fatty acid profile. The results showed that the peroxide value, p-Anisidine value, and total oxidation value of BRKSO were significantly higher than the MRKSO at day 24. The total tocopherol and tocotrienol contents were reduced 66.1% and 56.8% in BRKSO and MRKSO, respectively, upon the storage. There was a reduction of 71.7% and 23.5% of phytosterol content in BRKSO and MRKSO, respectively, upon the storage. The degradation rate of polyunsaturated fatty acids in BRKSO was higher than that of MRKSO. This study showed that the current microencapsulation technique is a feasible way to retard the oxidation of kenaf seed oil.
PRACTICAL APPLICATION: There is increasing research on the functional properties of crude kenaf seed oil, but the crude kenaf seed oil is not edible. This study offered in developing of microencapsulated refined kenaf seed oil by spray drying, which is suitable for food application. The microencapsulation of refined kenaf seed oil with healthier wall materials is beneficial in developing a diversity of functional food products and supplements.
Teaching Video NeuroImages: Purposeless groaning in progressive supranuclear palsy

Low SC, Tan AH, Lim SY

Neurology, 2017 01 03;88(1):e9.
PMID: 28025406 DOI: 10.1212/WNL.0000000000003465
Index of suspicion with appropriate timing of CT scan helps prevent missed diagnosis in urologic trauma

Sabrina B, Tan KL, Johann FK, Andre D

Med J Malaysia, 2018 08;73(4):255-256.
PMID: 30121691 MyJurnal

Ureteric and bladder injuries are uncommon, difficult to diagnose and rarely occur in isolation. Diagnosis is often delayed or missed at presentation. Therefore, high clinical suspicion and appropriate timing of computed tomography (CT) are of paramount importance. We report two cases (ureteropelvic junction avulsion and ruptured dome of bladder) whereby the presentations were subtle and would have been missed if not for high clinical suspicion. This article discusses the problems associated with these urologic injuries, as well as how to develop a high index of suspicion based on the pattern of anatomical disruption, mechanism of injury, physiological abnormality and comorbidity.
Xanthomatous meningioma: A metaplastic or degenerative phenomenon?

Wong YP, Tan GC, Kumar R

Neuropathology, 2018 Dec;38(6):619-623.
PMID: 30187570 DOI: 10.1111/neup.12511

Xanthomatous changes can be observed in various conditions including primary xanthomatosis that is linked to an underlying hypercholesterolemia and more commonly associated with secondary xanthomatous degenerative processes in neoplasm and chronic inflammation. Meningioma with extensive xanthomatous change is exceedingly rare. The presence of cholesterol clefts within this peculiar meningioma subtype has not been described. Herein, we report an unusual case of xanthomatous meningioma in an 83-year-old normolipidemic woman, who presented to us with worsening lower limb weakness and global aphasia. There was increasing evidence to suggest that the presence of xanthomatous changes in long-standing meningioma is merely a sequela of cellular degeneration rather than true metaplastic change as previously hypothesized. Hence, the diagnosis of "xanthomatous meningioma" in the metaplastic category should be revisited and considered as a distinct histological subtype. The possible histogenesis of such intriguing phenomenon is discussed with a review of the literature.
Effect of FTO rs9930506 on obesity and interaction of the gene variants with dietary protein and vitamin E on C-reactive protein levels in multi-ethnic Malaysian adults

Mitra SR, Tan PY, Amini F

J Hum Nutr Diet, 2018 12;31(6):758-772.
PMID: 30141234 DOI: 10.1111/jhn.12593

BACKGROUND: Individual variations of obesity-related traits can be a consequence of dietary influence on gene variants.
METHODS: This cross-sectional study aimed to evaluate (i) the effect of FTO rs9930506 on obesity and related parameters and (ii) the influence of diet on the above association in Malaysian adults. In total, 79 obese and 99 nonobese Malaysian adults were recruited.
RESULTS: In comparison with Chinese and Malays, Indians had significantly higher waist circumference (P ≤ 0.001 and P = 0.016), waist-hip ratio (P = 0.001 and P < 0.001), body fat percentage (P = 0.001 and P = 0.042), fasting insulin (P = 0.001 and P = 0.001), homeostatic model assessment-insulin resistance (P = 0.001 and P = 0.001) and lower high-density lipoprotein-cholesterol levels (P < 0.001 and P < 0.001), respectively. Indians consumed significantly lower dietary cholesterol (P = 0.002), percentage energy from protein (P < 0.001) and higher fibre (P = 0.006) compared to the other two groups. Malaysian Indians expressed the highest risk allele frequency (G) of FTO rs9930506 compared to the Malays and the Chinese (P < 0.001). No significant association was found between FTO rs9930506 and obesity (dominant model). Risk allele carriers (G) consumed significantly lower vitamin E (P = 0.020) and had a higher fibre intake (P = 0.034) compared to the noncarriers (A). Gene-diet interaction analysis revealed that risk allele carriers (G) had lower high sensitivity C-reactive protein (hsCRP) levels with higher energy from protein (≥14% day-1 ; P = 0.049) and higher vitamin E (≥5.4 mg day-1 ; P = 0.038).
CONCLUSIONS: The presence of the risk allele (G) of FTO rs9930506 was not associated with an increased risk of obesity. Malaysian Indians had a significantly higher frequency of the risk allele (G). Indian participants expressed higher atherogenic phenotypes compared to Chinese and Malays. FTO rs9930506 may interact with dietary protein and vitamin E and modulate hsCRP levels.
Fulltext Begoniayenyeniae (Begoniaceae), a new species from Endau Rompin National Park, Johor, Malaysia

Tan JP, Tam SM, Kiew R

PhytoKeys, 2018.
PMID: 30416344 DOI: 10.3897/phytokeys.110.25846

Begoniayenyeniae is a new species of horticultural value known only from the Endau Rompin National Park, Peninsular Malaysia. It is similar to Begoniarajah with which it had previously been confused in the number of tepals and leaf characters. The new species is compared with three similar species, B.foxworthyi, B.rajah and B.reginula and photographs of all four species and descriptions of B.yenyeniae and B.rajah are provided. Molecular analysis using the ndhF-rpl132 chloroplast marker confirms the four species as distinct. Amongst native species, the three variegated species, B.yenyeniae, B.rajah and B.reginula, are some of the most popular Malaysian begonias in cultivation. Based on its restricted distribution, Begoniayenyeniae, under the IUCN Red List Categories and Criteria, is assessed as Critically Endangered.
Atypical Presentation of Pyogenic Granuloma of the Right Index Finger: A Rare Case Report

Tan LS, Daud MH, Nasirudin N

J Hand Surg Asian Pac Vol, 2018 Dec;23(4):577-580.
PMID: 30428790 DOI: 10.1142/S2424835518720335

Pyogenic granuloma, also known as lobular capillary hemangioma, is a benign vascular lesion of the skin or mucous membrane with rapid growth or repetitive trauma. Rarely seen in adult, its management varies and surgical intervention is usually common. We report a case of pyogenic granuloma of the right index finger in a 46-year-old gentleman who presented with painless swelling of the right index finger after a trivial injury. Wedge biopsy confirmed the diagnosis and excision of the granuloma measuring 3 cm × 3 cm × 2 cm was done with curettage and electrocautery over the base of granuloma. The wound subsequently healed well with good functional and aesthetic outcome.
Fulltext Proteomic profiling of senescent human diploid fibroblasts treated with gamma-tocotrienol

Tan JK, Jaafar F, Makpol S

BMC Complement Altern Med, 2018 Nov 29;18(1):314.
PMID: 30497457 DOI: 10.1186/s12906-018-2383-6

BACKGROUND: Replicative senescence of human diploid fibroblasts (HDFs) has been used as a model to study mechanisms of cellular aging. Gamma-tocotrienol (γT3) is one of the members of vitamin E family which has been shown to increase proliferation of senescent HDFs. However, the modulation of protein expressions by γT3 in senescent HDFs remains to be elucidated. Therefore, this study aimed to determine the differentially expressed proteins (DEPs) in young and senescent HDFs; and in vehicle- and γT3-treated senescent HDFs using label-free quantitative proteomics.
METHODS: Whole proteins were extracted and digested in-gel with trypsin. Peptides were detected by Orbitrap liquid chromatography mass spectrometry. Mass spectra were identified and quantitated by MaxQuant software. The data were further filtered and analyzed statistically using Perseus software to identify DEPs. Functional annotations of DEPs were performed using Panther Classification System.
RESULTS: A total of 1217 proteins were identified in young and senescent cells, while 1218 proteins in vehicle- and γT3-treated senescent cells. 11 DEPs were found in young and senescent cells which included downregulation of platelet-derived growth factor (PDGF) receptor beta and upregulation of tubulin beta-2A chain protein expressions in senescent cells. 51 DEPs were identified in vehicle- and γT3-treated senescent cells which included upregulation of 70 kDa heat shock protein, triosephosphate isomerase and malate dehydrogenase protein expressions in γT3-treated senescent cells.
CONCLUSIONS: PDGF signaling and cytoskeletal structure may be dysregulated in senescent HDFs. The pro-proliferative effect of γT3 on senescent HDFs may be mediated through the stimulation of cellular response to stress and carbohydrate metabolism. The expressions and roles of these proteins in relation to cellular senescence are worth further investigations. Data are available via ProteomeXchange with identifier PXD009933.
Fulltext Piloting an Asia Pacific Research Forum (pASPAREF)

Tan NC, Ng CJ, Ng M

Asia Pac Fam Med, 2002;1(2&3):110.
Deoxygenation of pyrolysis vapour derived from durian shell using catalysts prepared from industrial wastes rich in Ca, Fe, Si and Al

Tan YL, Hameed BH, Abdullah AZ

Sci Total Environ, 2020 Feb 10;703:134902.
PMID: 31753498 DOI: 10.1016/j.scitotenv.2019.134902

Catalysts prepared from industrial wastes rich in Fe, Ca, Si, and Al were used in catalytic upgrading of pyrolysis vapour derived from durian shell and their effect on product yield and properties were compared. With same silica-to-alumina ratio, catalyst prepared from oil palm ash (AS-OPA) with lower Fe and Ca contents gave higher liquid yield (8.32 wt%) with alcohols (28.90%), hydrocarbons (46.00%), and nitrogen-containing compounds (21.46%) while catalyst prepared from electric arc furnace slag (AS-EAF) with higher Fe and Ca contents produced lower liquid yield (50.21 wt%) with high amount of esters (25.80%) and hydrocarbons (72.82%). The presence of AS-OPA and AS-EAF catalysts enhanced deoxygenation degree of bio-oil to 81.13% and 85.49%, respectively. The catalytic performance of AS-EAF at different temperatures (400-600 °C) and AS-EAF/durian shell ratios (1:30, 2:30, 3:30) was investigated. Increasing catalytic temperature enhanced production of bio-oil, reduced oxygenates and enhanced formation of esters. The liquid yield and yield of esters decreased with increasing catalyst loading. Hydrocarbons (mainly neopentane) were the major chemical compounds found in bio-oil produced over AS-EAF. Besides that, AS-EAF showed good deoxygenation performance with highest selectivity of hydrocarbons at 500 °C and AS-EAF/durian shell ratio of 2:30. Catalytic fast pyrolysis of durian shell using waste-derived catalysts is an effective waste management strategy as the bio-oil produced can be a potential alternative source of energy or chemical feedstocks.
Fulltext Two-Step Purification of Glycerol as a Value Added by Product From the Biodiesel Production Process

Abdul Raman AA, Tan HW, Buthiyappan A

Front Chem, 2019;7:774.
PMID: 31799239 DOI: 10.3389/fchem.2019.00774

For every ton of biodiesel produced, about 100 kg of glycerol is also generated as a by-product. The traditional method of removing glycerol is mainly by gravity separation or centrifugation. This method generates crude glycerol, which may still contain impurities such as methanol, oil, soap, salt, and other organic materials at ppm levels. The effective usage of crude glycerol is important to improve the economic sustainability of the biodiesel industry while reducing the environmental impacts caused by the generated waste. The application and value of crude glycerol can be enhanced if these impurities are removed or minimized. Thus, it is important to develop a method which can increase the economic and applicable value of crude glycerol. Therefore, in the present study, the dual step purification method comprised of acidification and ion exchange techniques has been used to purify the crude glycerol and convert it into higher-value products. The acidification process started with the pH adjustment of the crude glycerol, using phosphoric acid to convert soap into fatty acid and salts. Then, the pretreated glycerol was further purified by ion exchange with a strong cation H+ resin. Gas chromatography (GC) was used to analyze both crude and purified glycerol and expressed as the weight percentage of glycerol content. A maximum glycerol purity of 98.2% was obtained after the dual step purification method at the optimized conditions of 60% of solvent, the flow rate of 15 mL/min and 40 g of resin. Further, the glycerol content measured being within the accepted amount of BS 2621:1979. Therefore, this study has proven that the proposed crude glycerol purification process is effective in improving the glycerol purity and could enhance the applicability of glycerol in producing value-added products which bring new revenue to the biodiesel industry.

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