Displaying publications 41 - 60 of 114 in total

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  1. Fulltext Mercury levels of marine fish commonly consumed in Peninsular Malaysia
    Ahmad NI, Noh MF, Mahiyuddin WR, Jaafar H, Ishak I, Azmi WN, et al.
    Environ Sci Pollut Res Int, 2015 Mar;22(5):3672-86.
    PMID: 25256581 DOI: 10.1007/s11356-014-3538-8
    This study was conducted to determine the concentration of total mercury in the edible portion of 46 species of marine fish (n = 297) collected from selected major fish landing ports and wholesale markets throughout Peninsular Malaysia. Samples were collected in June to December 2009. Prior to analysis, the fish samples were processed which consisted of drying at 65 °C until a constant weight was attained; then, it was grounded and digested by a microwave digestion system. The analytical determination was carried out by using a mercury analysis system. Total mercury concentration among fish species was examined. The results showed that mercury concentrations were found significantly higher (p 20 cm) and were positively related with fish size (length and weight) in all fish samples. Despite the results, the level of mercury in marine fish did not exceed the permitted levels of Malaysian and JECFA guideline values at 0.5 mg/kg methylmercury in fish.
    Matched MeSH terms: Mercury/analysis*; Methylmercury Compounds/analysis*
  2. Optimisation of the supercritical extraction of toxic elements in fish oil
    Hajeb P, Jinap S, Shakibazadeh Sh, Afsah-Hejri L, Mohebbi GH, Zaidul IS
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2014;31(10):1712-22.
    PMID: 25090228 DOI: 10.1080/19440049.2014.942707
    This study aims to optimise the operating conditions for the supercritical fluid extraction (SFE) of toxic elements from fish oil. The SFE operating parameters of pressure, temperature, CO2 flow rate and extraction time were optimised using a central composite design (CCD) of response surface methodology (RSM). High coefficients of determination (R²) (0.897-0.988) for the predicted response surface models confirmed a satisfactory adjustment of the polynomial regression models with the operation conditions. The results showed that the linear and quadratic terms of pressure and temperature were the most significant (p < 0.05) variables affecting the overall responses. The optimum conditions for the simultaneous elimination of toxic elements comprised a pressure of 61 MPa, a temperature of 39.8ºC, a CO₂ flow rate of 3.7 ml min⁻¹ and an extraction time of 4 h. These optimised SFE conditions were able to produce fish oil with the contents of lead, cadmium, arsenic and mercury reduced by up to 98.3%, 96.1%, 94.9% and 93.7%, respectively. The fish oil extracted under the optimised SFE operating conditions was of good quality in terms of its fatty acid constituents.
    Matched MeSH terms: Mercury/analysis; Mercury/isolation & purification
  3. Optimizing conditions for methylmercury extraction from fish samples for GC analysis using response surface methodology
    Hajeb P, Jinap S, Abu Bakar F, Bakar J
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2009 Jun;26(6):829-38.
    PMID: 19680957 DOI: 10.1080/02652030902751704
    Response surface methodology (RSM) was used to determine the optimum experimental conditions to extract methylmercury from fish samples for GC analysis. The influence of four variables - acid concentration (3-12 M), cysteine concentration (0.5-2% w/v), solvent volume (3-9 ml) and extraction time (10-30 min) - on recovery of methylmercury was evaluated. The detection limit for methylmercury analysis using a microelectron capture detector was 7 ng g(-1) in fish samples. The mean recovery under optimum conditions was 94%. Experimental data were adequately fitted into a second-order polynomial model with multiple regression coefficients (r(2)) of 0.977. The four variables had a significant effect (p < 0.05) on the recovery of methylmercury from a reference material (BCR-463). Optimum conditions for methylmercury extraction were found using an acid concentration of 12.2 M, cysteine concentration of 2.4%, solvent volume of 1.5 ml and extraction time of 35 min. The validation of the developed method to analyze methylmercury in fish samples exhibited good agreement with mercury content in the samples.
    Matched MeSH terms: Mercury/analysis*; Methylmercury Compounds/analysis*
  4. Effects of washing pre-treatment on mercury concentration in fish tissue
    Hajeb P, Jinap S
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2009 Oct;26(10):1354-61.
    PMID: 19690999 DOI: 10.1080/02652030903150567
    The objective of this study was to examine the effect of washing pre-treatment on mercury concentration in fish fillet. Response surface methodology was used to investigate the influence of three variables, pH (1-6.5), NaCl (0-1% w/v) and exposure time (5-30 min) by using a three-factor central composite design. The aim was to obtain the best possible combination of these variables in order to reduce mercury in fish fillet. The experimental data were adequately fitted into a second-order polynomial model with multiple regression coefficients (R(2)) of 0.961. The results indicated that the reduction of mercury in fish flesh significantly depends on the pH of the solution used. The overall optimal condition resulting in the maximum mercury reduction in fish fillet was obtained at a combined level pH of 2.79, NaCl of 0.5% and exposure time of 13.5 min. The optimized protocol produced a solution that can reduce mercury from raw fish fillet up to 81%.
    Matched MeSH terms: Mercury/chemistry*
  5. Heavy metals in spices and herbs from wholesale markets in Malaysia
    Nordin N, Selamat J
    Food Addit Contam Part B Surveill, 2013;6(1):36-41.
    PMID: 24786623 DOI: 10.1080/19393210.2012.721140
    As, Cd, Pb and Hg were analysed in commonly consumed spices and herbs in Malaysia. The range of As, Cd, Pb and Hg content was 0.24-2.54, 0.23-8.07, 1.54-8.94 and 0.06-0.52 µg g(-1), respectively. The highest concentration of Cd, Pb and Hg in spices and herbs exceeded the maximum permitted proportion, which are 1, 2 and 0.05 µg g(-1), respectively. This study suggests further monitoring of Cd, Pb and Hg on daily consumption of spices and herbs and its toxicological implication for consumers since only the amount of As was lower than the permitted concentration.
    Matched MeSH terms: Mercury/analysis
  6. Contamination of mercury in tongkat Ali hitam herbal preparations
    Ang HH, Lee KL
    Food Chem Toxicol, 2006 Aug;44(8):1245-50.
    PMID: 16567029 DOI: 10.1016/j.fct.2006.01.014
    The DCA (Drug Control Authority), Malaysia has implemented the phase three registration of traditional medicines on 1 January 1992. As such, a total of 100 products in various pharmaceutical dosage forms of a herbal preparation found in Malaysia, containing tongkat Ali hitam, either single or combined preparations, were analyzed for the presence of a heavy toxic metal, mercury, using atomic absorption spectrophotometer, after performing a simple random sampling to enable each sample an equal chance of being selected in an unbiased manner. Results showed that 26% of these products possessed 0.53-2.35 ppm of mercury, and therefore, do not comply with the quality requirement for traditional medicines in Malaysia. The quality requirement for traditional medicines in Malaysia is not exceeding 0.5 ppm for mercury. Out of these 26 products, four products have already registered with the DCA, Malaysia whilst the rest, however, have not registered with the DCA, Malaysia.
    Matched MeSH terms: Mercury/analysis*
  7. Effects of additional cysteine in fish diet on mercury concentration
    Mok WJ, Hatanaka Y, Seoka M, Itoh T, Tsukamasa Y, Ando M
    Food Chem, 2014 Mar 15;147:340-5.
    PMID: 24206728 DOI: 10.1016/j.foodchem.2013.09.157
    Mercury contamination, especially of seafood, continues to attract public concern. Cysteine, NH2CH(CH2SH)COOH, is a naturally occurring hydrophobic amino acid that contains a thiol group. The purpose of our study was to investigate the use of the additive cysteine in fish diets to reduce mercury concentration in fish, and to observe the effectiveness of dietary cysteine in fish livers. Diets containing 1% and 10% cysteine successfully decreased mercury concentrations in fish compared with the 0% cysteine diet. The liver may have formed excessive lipid droplets or was unable to mobilize lipid stores during exposure to mercury; additional cysteine could help to mobilize excessive lipids in it.
    Matched MeSH terms: Mercury/analysis; Mercury/metabolism*
  8. Characterization of edible bird's nest of different production, species and geographical origins using nutritional composition, physicochemical properties and antioxidant activities
    Quek MC, Chin NL, Yusof YA, Law CL, Tan SW
    Food Res Int, 2018 07;109:35-43.
    PMID: 29803459 DOI: 10.1016/j.foodres.2018.03.078
    Edible bird's nest (EBN) is a precious food made from the solidified saliva of swiftlets. EBN from three types of origin, namely production, swiftlet species and geographical were characterised based on its nutritional composition, physicochemical properties and antioxidant properties. Proximate composition, total phenolic content (TPC) and antioxidant activities were determined following official methods, while mineral and heavy metal contents were obtained by respective atomic adsorption spectrometry (AAS) and inductively coupled plasma-mass spectrometry (ICP-MS). Amino acids profile and sialic acid were determined using high performance liquid chromatography (HPLC). Calcium and sodium were the major elements in EBN samples at averages of 17,267 mg/kg and 13,681 mg/kg, respectively. Despite protein contents were not significantly different; interestingly the total amino acids in A. fuciphagus EBN, 64.57 g/100 g was found to be 23% higher than in A. maximus EBN. EBN from house, A. fuciphagus and Peninsular Malaysia had greater antioxidant activities, 2.33-3.49 mg AAE/g and higher sialic acid, 13.57 g/100 g while those from cave, A. maximus and East Malaysia contained more minerals like calcium and magnesium. The 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and ferric ion reducing antioxidant power (FRAP) of house, A. fuciphagus and Peninsular Malaysia EBNs were approximately 2 times greater than the others. All samples were complied with the Malaysian Standard MS 2334:2011, except for mercury and nitrite. The overall findings suggest that the quality of EBN was varied following the production, species and geographical origins.
    Matched MeSH terms: Mercury
  9. Fulltext Bioremediation and Electricity Generation by Using Open and Closed Sediment Microbial Fuel Cells
    Abbas SZ, Rafatullah M, Khan MA, Siddiqui MR
    Front Microbiol, 2018;9:3348.
    PMID: 30692985 DOI: 10.3389/fmicb.2018.03348
    The industrial contamination of marine sediments with mercury, silver, and zinc in Penang, Malaysia was studied with bio-remediation coupled with power generation using membrane less open (aerated) and closed (non-aerated) sediment microbial fuel cells (SMFCs). The prototype for this SMFC is very similar to a natural aquatic environment because it is not stimulated externally and an oxygen sparger is inserted in the cathode chamber to create the aerobic environment in the open SMFC and no oxygen supplied in the closed SMFC. The open and closed SMFCs were showed the maximum voltage generation 300.5 mV (77.75 mW/m2) and 202.7 mV (45.04 (mW/m2), respectively. The cyclic voltammetry showed the oxidation peak in open SMFCs at +1.9 μA and reduction peak at -0.3 μA but in closed SMFCs oxidation and reduction peaks were noted at +1.5 μA and -1.0 μA, respectively. The overall impedance (anode, cathode and solution) of closed SMFCs was higher than open SMFCs. The charge transfer impedance showed that the rates of substrate oxidation and reduction were very low in the closed SMFCs than open SMFCs. The Nyquist arc indicated that O2 act as electron acceptor in the open SMFCs and CO2 in the closed SMFCs. The highest remediation efficiency of toxic metals [Hg (II) ions, Zn (II) ions, and Ag (I) ions] in the open SMFCs were 95.03%, 86.69%, and 83.65% in closed SMFCs were 69.53%, 66.57%, and 65.33%, respectively, observed during 60-80 days. The scanning electron microscope and 16S rRNA analysis showed diverse exoelectrogenic community in the open SMFCs and closed SMFCs. The results demonstrated that open SMFCs could be employed for the power generation and bioremediation of pollutants.
    Matched MeSH terms: Mercury
  10. Fulltext Fresh water aquaculture fish consumption in Malaysia and heavy metals risk exposure to consumers
    Ibrahim, A.B., Mohd Khan, A., Norrakiah, A.S., Intan Fazleen, Z.
    International Food Research Journal, 2014;21(6):2109-2113.
    MyJurnal
    This study aimed to determine the amount of the fish (Oreachromi sp, Clarias sp. and Pangasius sutchii) consumption in Malaysia; the quantity of heavy metal residues (arsenic, cadmium, mercury and plumbum) in the fish and the level of the risk exposure. About 1440 respondents from six main production districts were randomly interviewed and the body weight of the respondents was also measured. A total of 240 ready to eat fish from food premises were also stratified randomly sampled where each sample was weighted to determine the average weight of one serving unit sold at food premises. The heavy metal residues were analyzed using Inductively Coupled Plasma–Optical Emission Spectrometer (ICP-OES) Optima 4300 DV (German). The level of heavy metals risk exposure was calculated as the percentage value of ’Provisional Tolerable Weekly Intakes’ (PTWI) and recalculated using computer programme @Risk 4.5 Excel (Palisade, USA). The result showed that 60.3% of the respondents consumed the fish. The level of heavy metal risk exposures were calculated as very low i.e. 0.14% (As), 0.31% (Cd), 0.09% (Hg) and 0.78% (Pb).
    Matched MeSH terms: Mercury
  11. Fulltext Heavy metals (mercury, arsenic, cadmium, plumbum) in selected marine fish and shellfish along the Straits of Malacca
    Alina, M., Azrina, A., Mohd Yunus, A.S., Mohd Zakiuddin, S., Mohd Izuan Effendi, H., Muhammad Rizal, R.
    International Food Research Journal, 2012;19(1):135-140.
    MyJurnal
    Level of heavy metals in marine ecosystem has been intensively studied during recent years as these hazardous substances could be accumulated in the biota. Generally, the presence of contaminants in fish is a result of human activities such as industrial and agricultural wastes. In this study, the marine fish and shellfish from the Straits of Malacca were analyzed using Inductively Coupled Plasma Optical Emission Spectrophotometer (ICP-OES) and Flow Injection Mercury System (FIMS) for Cd, As and Pb and Hg, respectively. The Straits of Malacca is one of the busiest shipping routes in the world that make the level of heavy metals potentially high besides the various industrial activities along the west region of Peninsular Malaysia. The range of heavy metals in samples were 1.0-3-6.5-3 µg/ g wet sample for Hg, 0.5-2-47-2 µg/ g wet sample for Cd, 0.01-0.39 µg/ g wet sample for Pb and 0.14-6.57 µg/ g wet sample for As. Most part of the values was below the permitted limit set by FAO/WHO 2004 as well as Food Act 1983 and Food Regulations 1985. Therefore it can be generalized that fish and shellfish from the Straits of Malacca are safe to consume in terms of these heavy metals concentrationand do not constitute a risk for human health.
    Matched MeSH terms: Mercury
  12. Fulltext An exotic fruit with high nutritional value: Kadsura coccinea fruit
    Sun, J., Jiang, Y., Amin, I., Li, Z., Prasad, K.N., Duan, X., et al.
    International Food Research Journal, 2011;18(2):651-657.
    MyJurnal
    This research was to determine nutritional composition, essential and toxic elemental content, and major phenolic acid with antioxidant activity in Kadsura coccinea fruit. The results indicated that Kadsura coccinea fruit exhibited the high contents of total protein, total fat, ash and essential elements such as calcium (Ca), ferrum (Fe) and phosphorus (P). The levels of four common toxic elements, i.e. cadmium (Cd), mercury (Hg), arsenic (As) and lead (Pb), were lower than legal limits. By high-performance liquid chromatography (HPLC) analysis, gallic acid was identified as major phenolic acid in peel and pulp tissues. Its contents were no significant difference in both tissues. In comparison with two commercial antioxidants, the major phenolic acid extracted from Kadsura coccinea exhibited stronger 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity and reducing power. Kadsura coccinea fruit is a good source of nutrition and natural antioxidant. It is worthwhile to popularize this exotic fruit around the world.
    Matched MeSH terms: Mercury
  13. Fulltext Preliminary studies on the evaluation of nutritional composition of unripe and ripe ‘Kundang’ fruits (Bouea macrophylla Griffith)
    Rajan, Nithiya Shanmuga, Bhat,Rajeev, Karim, A.A.
    International Food Research Journal, 2014;21(3):985-990.
    MyJurnal
    Unripe and ripe kundang fruits (Bouea macrophylla Griffith) is either consumed fresh or is cooked in Malaysia. In this study composition of unripe and ripe fruits (proximate, amino acids profile, minerals and heavy metal contents) were evaluated. Results obtained showed unripe kundang fruit to possess higher moisture, ash, crude lipid, crude fiber and crude protein contents than the ripe fruits. With regard to amino acid contents, unripe fruits had higher content of essential amino acids. The unripe and ripe fruits were found to be rich in essential minerals with potassium (K) to be in abundance. Heavy metals such as cadmium, nickel, mercury, lead and arsenic, were detected in trace amounts (< 5.0 mg/kg) in both unripe and ripe fruits. Through this investigation, it is concluded that both unripe and ripe fruits to posses’ adequate amount of nutritionally important compounds beneficial to human health and can be explored for commercial purposes.
    Matched MeSH terms: Mercury
  14. Fulltext Molecular phylogenetic analysis of wild Tiger’s milk mushroom (Lignosus rhinocerus) collected from Pahang, Malaysia and its nutritional value and toxic metal content
    Lai WH, Loo SS, Rahmat N, Shaharuddin S, Daud F, Zamri Z, et al.
    International Food Research Journal, 2013;20(5):2301-2307.
    MyJurnal
    Tiger’s Milk mushroom has been used for medicinal purposes by local aborigines to treat asthma, breast cancer, cough, fever and food poisoning. Molecular phylogenetic analysis utilizing RNA polymerase II, second largest subunit (RPB2) gene, identified the wild Tiger’s Milk mushrooms collected from the state of Pahang in Malaysia for this study as Lignosus rhinocerus in the order Polyporales. The tuber, stipe and pileus of this mushroom were analyzed for their basic nutritional composition (fat, protein, and carbohydrate) and toxic metal content profile (Cadmium, Lead and Mercury). The moisture content of these mushroom parts varied from 32.22% (pileus) – 46.31% (stipe). The dry matter of the mushrooms contained 2.76% (stipe) – 6.60% (pileus) proteins, 0.21% (pileus) – 0.30% (tuber) fat, 1.76% (stipe) – 4.38% (tuber) ash and 38.47% (stipe) – 56.30% (pileus) carbohydrates. The toxic metal content of the mushroom samples ranged from 0.03–0.12 mg/kg for Cd, 0.80–1.94 mg/kg for Pb and 0.05–0.10 mg/kg for Hg. The present study demonstrated that L. rhinocerus is a potential source of food due to its high carbohydrate content. In addition, the trace levels of toxic metals in this mushroom are within the safe level for consumption.
    Matched MeSH terms: Mercury
  15. Fulltext Mineral and heavy metal contents of marine fin fish in Langkawi island, Malaysia
    Irwandi, J., Farida, O.
    International Food Research Journal, 2009;16(1):105-112.
    MyJurnal
    A study was conducted to quantitate the concentrations of heavy metals, such as Hg, Pb and Cd in eight species of marine fin fish caught off the coast of Langkawi Island in Malaysia, as well as in its waters. The same fish were also used to determine the content of nutritional minerals, such as copper (Cu), zinc (Zn), calcium (Ca), and manganese (Mn).Fish and water samples were collected from four different areas, namely (1) Main Jetty Pulau Tuba (MJPT), (2) Teluk Cempedak Jetty (TCJ), (3) Simpang Tiga Chian Lian (STCL) and (4) Main Jetty Kuah (MJK) around Langkawi Island. Results showed that for the vital elements, all species had higher concentration of Zn compared to other elements. For the toxic elements, lead (Pb) and mercury (Hg) were found to have lower concentration of the mean values than the permissible limits set by FAO/WHO (1984). However, cadmium (Cd) level was slightly higher than the permissible limit but was still acceptable according to the Malaysian Food Regulation (1985). It can be concluded that all fish species studied are safe to be consumed.
    Matched MeSH terms: Mercury
  16. Fulltext Composition of tree peony (Paeonia suffruticosa) and Chinese apple flower (Malus spp.) buds
    Voon, H.C., Bhat, Rajeev, Karim, A.A., Rosma, A.
    International Food Research Journal, 2013;20(3):1173-1179.
    MyJurnal
    Traditionally, in Chinese medicine, tree peony and apple flower buds are used to prepare herbal decoctions to cure various ailments. As both of these flowers are popular and used regularly, providing scientific evidence on their basic composition is a necessity. Hence, in the present study, we report the chemical composition of these two flower buds. Results revealed tree peony and apple flower buds to have high crude protein (15.73 and 26.30%), fibre (13.11 and 16.51%), and carbohydrate (57.84 and 40.63%) contents. Both the flowers had significant amounts of essential amino acids and unsaturated fatty acids. Essential minerals present in tree peony and apple flowers were potassium (1540.37 and 1125.60 mg/100 g), calcium (462.46 and 449.98 mg/100 g), magnesium (241.51 and 164.23 mg/100 g), sodium (12.75 and 20.06 mg/100 g), and phosphorus (420.00 and 590.00 mg/100 g), respectively. Heavy metals (cadmium, nickel, mercury, lead, and arsenic) were detected in trace amounts (< 0.50 mg/100 g) in both the flower buds. Results obtained indicate that both flowers could be exploited as an additional source of nutraceutical for the development of new functional foods.
    Matched MeSH terms: Mercury
  17. Fulltext Composition of amino Acids, fatty acids, minerals and dietary fiber in some of the local and import rice varieties of Malaysia
    Thomas, R., Bhat, Rajeev, Kuang, Y.T.
    International Food Research Journal, 2015;22(3):1148-1155.
    MyJurnal
    In this study, three popular, regionally grown rice varieties (Bario, brown and white) were compared with three of the most popular and highly marketed imported rice varieties (black, glutinous and basmati rice) in Penang region of Malaysia. Rice samples were evaluated for amino acids, fatty acids, minerals, heavy metals and dietary fiber composition. Overall, amino acids content among all the rice samples were comparable to each other. Results with regard to minerals showed potassium to be high in brown rice (197.41 mg/100g), while magnesium was recorded to be high in black rice (107.21 mg/100g). Heavy metals such as cadmium, nickel, mercury and lead, though present, they were in negligible amounts. Among all the rice varieties investigated, the total saturated fatty acid and unsaturated fatty acid content was highest in black rice (5.89%). The soluble dietary fiber was higher in white rice (16.39%), whereas insoluble dietary fiber was high in brown (16.51%) and black rice (14.49%), respectively. Results generated from this study is anticipated to benefit both the health wary consumers (based on their potential nutritional attributes) as well as the local food industries to choose the best rice variety while developing novel rice based food products.
    Matched MeSH terms: Mercury
  18. Establishing mercury-free medical facilities: a Malaysian case study
    Amir Sultan MM, Goh CT, Wan Puteh SE, Mokhtar M
    Int J Health Care Qual Assur, 2019 Feb 11;32(1):34-44.
    PMID: 30859864 DOI: 10.1108/IJHCQA-08-2017-0161
    PURPOSE: Mercury is widely used in medical and healthcare facilities as dental amalgam, mercury-added medical devices, thiomersal-containing vaccines, laboratory analysis and for other general applications despite the hazards. Various agencies consistently promote mercury-free medical facilities through mercury-free alternatives and better management practices, which are in line with the Minamata Convention on Mercury that aims to protect human health and environment from anthropogenic mercury release. The paper aims to discuss these issues.

    DESIGN/METHODOLOGY/APPROACH: The authors conducted a gap analysis on recommended practices gathered from the literature and current practices gathered through semi-structured interviews with Malaysian medical personnel. A life cycle approach was adopted covering mercury use: input, storage, handling, accident, waste disposal and governance phases.

    FINDINGS: The authors found that there are significant gaps between recommended and current mercury management practices. Analysis indicates improper mercury management as the main contributor to these gaps. The authors found from recommended practices that core components needing improvement include: mercury management action plan, mercury use identification team, purchasing policy, proper guidelines and monitoring systems.

    PRACTICAL IMPLICATIONS: This study helps us to understand mercury management practices and suggests essential steps to establish a mercury-free medical facility.

    ORIGINALITY/VALUE: This study explored the gaps between recommended and current mercury management practices in a medical facility and contributes to the Minamata Convention on Mercury aspirations.

    Matched MeSH terms: Mercury/adverse effects*
  19. Fulltext Removal of toxic mercury from petroleum oil by newly synthesized molecularly-imprinted polymer
    Khairi NA, Yusof NA, Abdullah AH, Mohammad F
    Int J Mol Sci, 2015;16(5):10562-77.
    PMID: 26006226 DOI: 10.3390/ijms160510562
    In recent years, molecularly-imprinted polymers (MIPs) have attracted the attention of several researchers due to their capability for molecular recognition, easiness of preparation, stability and cost-effective production. By taking advantage of these facts, Hg(II) imprinted and non-imprinted copolymers were prepared by polymerizing mercury nitrate stock solution (or without it) with methacrylic acid (MAA), 2-hydroxyl ethyl methacrylate (HEMA), methanol and ethylene glycol dimethacrylate (EGDMA) as the monomer, co-monomer solvent (porogen) and cross-linker, respectively. Thus, the formed Hg(II) imprinted polymer was characterized by using Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), Brunauer, Emmett and Teller (BET) and thermal gravimetric analysis (TGA). The separation and preconcentration characteristics of Hg(II) imprinted polymer were investigated by solid phase extraction (SPE) procedures, and an optimal pH of 7 was investigated as ideal. The specific surface area of the Hg(II) imprinted polymer was found to be 19.45 m2/g with a size range from 100 to 140 µm in diameter. The maximum adsorption capacity was observed to be 1.11 mg/g of Hg(II) imprinted beads with 87.54% removal of Hg(II) ions within the first 5 min. The results of the study therefore confirm that the Hg(II) imprinted polymer can be used multiple times without significantly losing its adsorption capacity.
    Matched MeSH terms: Mercury/isolation & purification*
  20. Fulltext Artificial Neural Network Approach for Modelling of Mercury Ions Removal from Water Using Functionalized CNTs with Deep Eutectic Solvent
    Fiyadh SS, AlOmar MK, Binti Jaafar WZ, AlSaadi MA, Fayaed SS, Binti Koting S, et al.
    Int J Mol Sci, 2019 Aug 28;20(17).
    PMID: 31466219 DOI: 10.3390/ijms20174206
    Multi-walled carbon nanotubes (CNTs) functionalized with a deep eutectic solvent (DES) were utilized to remove mercury ions from water. An artificial neural network (ANN) technique was used for modelling the functionalized CNTs adsorption capacity. The amount of adsorbent dosage, contact time, mercury ions concentration and pH were varied, and the effect of parameters on the functionalized CNT adsorption capacity is observed. The (NARX) network, (FFNN) network and layer recurrent (LR) neural network were used. The model performance was compared using different indicators, including the root mean square error (RMSE), relative root mean square error (RRMSE), mean absolute percentage error (MAPE), mean square error (MSE), correlation coefficient (R2) and relative error (RE). Three kinetic models were applied to the experimental and predicted data; the pseudo second-order model was the best at describing the data. The maximum RE, R2 and MSE were 9.79%, 0.9701 and 1.15 × 10-3, respectively, for the NARX model; 15.02%, 0.9304 and 2.2 × 10-3 for the LR model; and 16.4%, 0.9313 and 2.27 × 10-3 for the FFNN model. The NARX model accurately predicted the adsorption capacity with better performance than the FFNN and LR models.
    Matched MeSH terms: Mercury/chemistry*
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