Abstract: The aim of this study was to investigate the use of liver moss (Dumortiera hirsute Sw. nees) as an alternative adsorbent for the removal of nickel, copper and cadmium from aqueous solution. The results showed that equilibrium contact time was 60 min and acidic pH was favourable for removal of metal ions. Higher initial metal ion concentrations led to lower removal. The data were fitted well both Langmuir and Freundlich isotherms. The monolayer adsorption capacities were 30.675, 35.971 and 53.476 mg/g for nickel, copper and cadmium, respectively. The presence of metal ions such as sodium, potassium and magnesium at concentration of 10 mM was found to have no significant effect on the removal of nickel, copper and cadmium. The removal of nickel, copper and cadmium was markedly inhibited, however, in the presence of calcium ion and heavy metal ions mixture in solutions. The kinetic data for removal processes were described by the pseudo-second-order model. The liver moss shows high potential as an economic and abundant material for the removal of metal ions from aqueous solution.
Abstract: Maltose is one of the starch derivatives. Maltose can be produced by starch hydrolysis using any kind of hydrolytic process. One of the methods to separate a mixture of both compounds is using porous membrane. In this research, a novel type of hybrid membrane was prepared from a mixture of cellulose acetate and silica fume. Silica fume is widely used in the domain of construction as cement material, whereas in this research silica fume was successfully used as membrane material. Various compositions of membrane dope solutions were prepared for obtaining the membranes used for separation of starch and maltose. Such synthesized membranes demonstrate a good performance in separation processes. The best performance is achieved when the composition of cellulose acetate in membrane dope solution is 15 % (w/w) in N,N-dimethylacetamide solvent and the mass ratio between cellulose acetate and silica fume is 4:1. For this composition, the rejection of membranes towards starch and maltose is 87 and 2 %, respectively, at working pressure of 3 bar and compaction time of 2 h. Infrared spectrum indicates no new peaks are found compared to raw materialsâ spectral peaks. Thus, it can be concluded that the interaction between the cellulose acetate and silica fume is merely a physical type. From the observation of cross-sectional SEM images, we can remark that the morphology of such a membrane is porous. X-ray diffractogram indicates that the synthesized membranes are amorphous.
Abstract: A chelating resin of polystyrene divinylbenzene resin functionalized by 1-(2-pyridylazo) 2- naphtol (PSDVB-PAN) has been synthesized and its sorption properties have been investigated for preconcentration and determination of cadmium at μg/L level by flame atomic absorption spectrometry. The procedure is based on the sorption of Cd(II) ions on a minicolumn of synthesized chelating resin. The retained cadmium ions can be quickly eluted from sorbent material, with the eluent stream consisting of nitric acid solution, directly to the nebulizer burner system of the flame atomic absorption spectrometer. The sorption capacity of PSDVB-PAN was found to be 7.5 mg/g at optimum pH and the chelating resin showed rapid kinetic sorption. The sorption equilibrium of Cd(II) on synthesized chelating resin was achieved just in 15 minutes. Parameters such as the pH effect on the cadmium sorption, sample volume, the sorption capacity of resin, the cadmium desorption from the resin and the analytical characteristics of the procedure were studied for the quantitative recoveries of the analyte ions. The developed system allowed a throughput rate of 15 samples h-1 with a detection limit of 1.5 μg/L. Relative standard deviation for 5 replicated injections of 50 μg/ L was 1.8%. This procedure was applied for cadmium determination in river water samples collected from Citarum River, West Java, Indonesia.
Abstract: The separation of penicillin G from fermentation broth can be done by emulsion liquid membrane technique. The aim of this research is to establish the optimal conditions for the extraction and separation of penicillin G using emulsion liquid membrane technique. The optimal conditions were found to be at ratio of internal phase volume to membrane phase volume of 1:1 ; time of making emulsion, 1 min ; emulsion contact rate, 300 rpm; rate of stirring of emulsion, 2000 rpm ; rest time of emulsion, 13 min; concentration of penicillin G as external phase, 375 ppm; and concentration of surfactant, 5% (v/v). pH of internal phase is 8; pH of external phase 5; ratio of emulsion phase volume to external phase volume, 1:2 and concentration of carrier 2 mM. The concentration of penicillin G and phenylacetic acid from fermentation results were 24771 mg/L and 32675 mg/L. Extraction by emulsion liquid membrane technique gave the percentage of penicillin G 53.38% and phenylacetic acid 60.41%. The percentage phenylacetic acid which is still higher (60.41%) indicated that the penicillin G could not completely be separated from phenylacetic acid by emulsion liquid membrane technique.
Abstract: Synthetic dye-containing wastewaters from textile, paper, plastic and leather-tanning industries are a most common organic pollutant. Such dyes may be toxic not only to aquatic life, but also to human beings. Consequently, dye removal from wastewater significantly benefits the environment. The aim of this study was to investigate the effectiveness of phyrophyllite as an adsorbent for Congo Red dye from wastewater. Dye sorption rates were investigated in bench-scale studies. Evaluation of adsorption performance of phyrophyllite on Congo Red necessitated the determination of Langmuir and Freundlich isotherms. Adsorption of Congo Red on phyrophyllite was found to be in conformity with both isotherms. The adsorption capacity for phyrophyllite was found to increase with decrease in particle size and with increase in temperature and intensity of agitation. The results indicated that phyrophyllite was a good adsorbent for Congo Red from wastewaters.
Abstract: The determination of Sn(II) ion at trace levels using integrated gas-liquid separator-reactor with hydride generation-quartz furnace atomic absorption spectrophotometer (HG-QFAAS) has been done. This modified gas-liquid separator at various sizes was able to increase sensitivity in the determination of Sn(II) in solution. The acid reagent mixing techniques, sample and reductant optimally occurs in a coil reaction before they are going to the gas-liquid separators. The optimum conditions of parameter measurement in the determination of Sn ion with HG method are influenced by type and concentration of acid, and the concentration of reductant has been evaluated. This optimum parameters can increase of analytical performance simultantly, which is shown by detection limit 3.74 mg L-1 for 100 mL injection volume (3.74 pg Sn). The accuracy of measurement shown by the % recovery of the Sn determination in natural water sample at > 95%, indicate this technique is good to be applied for tin analysis at picogram level.
Abstract: Abstract â Objective: Ion-pair reversed-phase chromatography (IP-RP) has been investigated for speciation of dibutyltin (DBT), tributyltin (TBT), and triphenyltin (TPhT). The influence of several parameters (pH, alkyl chain length, concentration of the ion pair reagent) has been studied to determine the best chromatographic conditions. Methods: Separation of the three organotin compounds was achieved on a C8-bonded silica column using a mixture of methanol, water, and acetic acid (80:19:1) as eluent, containing 1 mmol/L decane sulfonic acid as ion pairing reagent. The eluates were detected on-line by hydride generation-quartz furnace atomic absorption spectrophotometry (HG-QFAAS). Results: The resolving power of this developed method for separation of the organotins species at above conditions was shown by the values of fundamental chromatographic parameters. The capacity factors (kâ) for DBT, TBT and TPhT species were 0.27, 2.54, and 5.92 respectively. Resolution (Rs) values for DBT-TBT and TBT-TPhT separation were 2.92 and 2.42 respectively, while the selectivity for DBT-TBT and TBT-TPhT were 9.76 and 3.50 respectively. Conclusion: The developed IP-RP-HG-QFAAS chromatography technique can separate DBT, TBT, and TPhT with good performance which is shown by the chromatographic parameters produced
Abstract: The usage of ion-pair reversed phase Chromatography (IP-RP) technique for speciation of dibutyltin
(DBT), tributyltin (TBT), and triphenyltin (TPhT) has been studied. These three species were able to
separate on an ion pair-reversed phase chromatographic column. The eluates were detected on line by
using hydride generation-quartz furnace atomic absorption spectrophotometry (HG-QFAAS) method.
The eluent consisted of a mixture of methanol: water:acetic acid with a composition of 80:19:1,
containing 1 mol L-1 decane sulfonate acid as ion pairing reagent. The pH of the eluent was adjusted
with 1 mol L-1 H2SO4. The separation of all of the species at the above conditions was good, as shown
by the values of fundamental chromatographic parameters. The capacity factor (k') for DBT, TBT and
TPhT species were 0.27, 2.54 and 5.92 respectively. The resolution (Rs) values for DBT-TBT and
TBT-TPhT separation were 2.92 and 2.42 respectively, while the selectivity for DBT-TBT and TBTTPhT
were 9.76 and 3.50 respectively. These data show the effectiveness of the developed
chromatographic system.
Abstract: Sorption of La(III), Nd(III), and Gd(III) ions with solven-timpregnated resins using bis(2-ethylhexyl)phosphoric acid
(D2EHPA) and tributhylphosphate (TBP) as extractants and Amberlite XAD-16 as a polymeric support has been
studied. The impregnated resins containing various amounts of extractants have been prepared by the wet and dry
methods. The effects of pH, types, of extractant, extractant content (extractants/resin ratios of 10/90, 20/80, 50/50,
60/40 wt.%) and contact time on sorption of those metalic ions have been investigated by batch method. The sorption
capacity of Amberlite XAD-16 resin previously prepared by the wet method with a 60/40 extractant/resin mass ratio for
TBP, D2EHPA/TBP, and D2EHPA were 104.3 mg/g, 99.1 mg/g and 86.2 mg/g resin, respectively. Meanwhile,
sorption capacity of Amberlite XAD-16 resin previously prepared by dry method was found to be 645 mg/g; 419.16
mg/g, and 386.9 mg/g resin, respectively. The sorption percentage of the studied metal ions was within the range of 90-
99% for TBP, D2EHPA/TBP and D2EHPA XAD-16 resins at 20/80 extractant/resin mass ratio.
Abstract: Separation and quantification of molybdenum (Mo) in raw phloem
sap from castor bean (Ricinus communis L.) was performed by size exclusion
chromatography (SEC) and further purification was performed using quantitative
preparative native continuous polyacrylamide gel electrophoresis (QPNCPAGE).
For elemental detection, an inductively coupled plasma quadrupole
mass spectrometer (ICP-QMS) was applied. Two different SEC columns were
utilized: column A, Sephadex G-50 SF (700mm24mm), and column B,
Sephadex G-25 M (28mm9mm). The protein content of the fractions was
determined by the Bradford method. Using column A, two peaks of Mo were
detected consisting of a main peak (MoA2) in the low molecular weight area
(<1.35 kDa), and a minor peak (MoA1, 30 kDa) at the void volume of the column. Both Mo species were detected at the ultraviolet (UV) active
absorption area of raw phloem sap. Two peaks of Mo were also detected using
column B, the first peak (MoB1) being at the same elution volume as the protein
of raw phloem sap, and the second one (MoB2) was eluted in the area of
1.5 to 2.4mL of elution volume. Raw phloem sap digested by proteinase
K-enzyme indicates a significant reduction of MoB1 peak, which suggests that
the peak may contain Mo bound to protein or polypeptides. The raw phloem
sap and SEC fraction containing highest Mo concentration (MoA2) were
furthermore separated by QPNC-PAGE. The result reveals that the
Mo-containing fraction from the raw phloem sap was eluted at the same retention
volume as the purified sample. This implies that the Mo species were also
successfully separated and purified using QPNC-PAGE.
Abstract: The application of Ion Pair-Reversed Phase chromatography (IP-RP) technique for speciation of dibutyltin (DBT), tributyltin (TBT) and triphenyltin (TPhT) species has been studied. All of the species were able to separate on an ion pair-reversed phase chromatographic column. The eluats were detected online by the use of Hydride Generation-Quartz Furnace Atomic Absorption Spectrophotometry (HG-QFAAS) method. The eluent consisted of a mixture of methanol : water : acetic acid with a composition of 80:19:1, containing 1 mM of decane sulfonate as ion pairing reagent. The pH of the eluent was adjusted with 1 M H2SO4. The separation of all the species at the above conditions was good, which was shown by the values of the fundamental chromatographic parameters. The capacity factor (k') for DBT, TBT and TPhT species were 0.27, 2.54 and 5.92 respectively. The resolution (Rs) values for DBT-TBT and TBT-TPhT separation were 2.92 and 2.42 respectively, while the selectivity for DBT-TBT and TBT-TPhT were 9.76 and 3.50, respectively. These data show the effectiveness of the developed chromatographic system.
Abstract: The separation and purification of penicillin G from phenyl acetic acid (PAA) is very difficult to be carried out because the two compounds are weak acids and the two compounds can change from one to another by influence of pH. The aim of this research is to establish the optimal conditions for the extraction and separation of penicillin G from phenylacetic acid using the emulsion liquid membrane technique. The optimal conditions were ratio of internal phase volume to membrane phase volume of 1:1; time of stiring for emulsion preparation of 1 minute; emulsion contact rate of 300 rpm; emulsion contact time of 15 minutes; rate of stirring of emulsion of 2000 rpm; rest time of emulsion of 13 minutes; concentration of penicillin G as external phase 375 ppm; and concentration of surfactant 5% (v/v). At these conditions penicillin G can be extracted and separated from phenylacetic acid with a separation factor of 19.3 and a contact time of 15 minutes. Thus the technique of emulsion liquid membrane may be used as a reasonably effective method to separate penicillin G from phenylacetic acid.
Abstract: Tuna fishes were collected in the Straits of
Messina (Italy), were dissected and dorsal muscles minced,
freeze-dried, ground and sieved. The obtained powder was stabilised by g-irradiation and filled into brown glass bottles.
The homogeneity and stability at +20 °C and +40°C
were verified with regards to the total arsenic, dimethylarsinic
acid and arsenobetaine contents. Ten laboratories
participated in the certification study. All participants had
demonstrated beforehand their ability to produce accurate
results for the As speciation in fish tissue. The certified
values are: total arsenic (4.8 ± 0.3) mg/kg, arsenobetaine
(52 ± 3) mmol/kg, dimethylarsinic acid (2.0 ± 0.3) mmol/kg.
The material is available from the BCR since early 1998.
Abstract: Six interlaboratory studies were organised by
the Standard, Measurement and Testing Programme of the
European Commission on the determination of arsenic species (arsenobetaine, arsenocholine, monomethylarsonic
acid, dimethylarsinic acid, As(III) and As(V)) in marine
matrices and soil. A step-by-step approach was used and a
meeting was held at the end of each study to help the participants
to discover errors and to improve their analytical
methods. The successive steps investigated the calibration
procedures on various solutions, the separation and derivatisation
techniques on solutions and extracts and the
extraction on mussel and fish tissues. All materials used
for the study were monitored for their stability. Verified
calibration solutions and compounds were distributed to
the participants in each exercise in order to trace calibration
problems. The agreement between the results improved
regularly and at the end of the six campaigns allowed
the certification of a reference material of tuna-fish
tissue (BCR-CRM 627) for its total arsenic, arsenobetaine
and dimethylarsinic acid contents.
Abstract: Separation and quantification of six arsenic
species have been performed in cod, tuna and mussel
samples by high performance liquid chromatography
(HPLC) using inductively coupled plasma-optical
emission spectrometry (ICP-OES) and hydride generation-
quartz furnace atomic absorption spectrometry
(HG-QFAAS) as detection techniques. It has been
shown that arsenic extraction with a water-methanol
(1:1) mixture is sufficiently quantitative for the cod and
tuna, in which arsenic is mainly present as arsenobetaine
(about 90% of total As extracted). In contrast,
only 60% of the element is extracted from the mussels
and the chromatograms obtained reveal the presence of
an unknown compound. Detection limits are in the gg
m1-1 range for the HPLC-ICP-OES technique (quantification
of arsenobetaine and arsenocholine) and in
the ng m1-1 range for the HPLC-HG-QFAAS system
(quantification of arsenite, arsenate, monomethylarsonic
and dimethylarsinic acids).
Abstract: Separation of four arsenic species (arsenite, arsenate, monomethylarsonic acid and dimethylarsinic acid) has been performed by Capillary Zone Electrophoresis using an electroosmotic now modifier (dodecyltriethylammonium dihydrogenphosphate, Q(12)) and UV detection at 190 nm. The best compromise between a good resolution of the peaks and the shortest time of analysis has been found for the following values of the different parameters considered: [Q(12)] = 10 mmol l(-1), V = -25 kV, pII 8, t = 30 degrees C. Under those conditions, detection limits are about 250 ng ml(-1) (in arsenic) for each species. Short-term and long-term repeatabilities have been demonstrated. Moreover, this method has been successfully applied to an artificial solution mimicking a fish extract.
Abstract: Logam kelompok platinum (palladium, rhodium, dan platinum) banyak digunakan sebagai katalis, khususnya autokatalis. Palladium dan logam kelompok platinum (Platinum Group Metal, PGM) lainnya juga semakin banyak digunakan untuk solid catalyst fuel cell. Selain sebagai katalis, saat ini tingkat konsumsi PGM sebagai logam-logam berharga (precious metals) juga sangat tinggi. Palladium dalam biji mineral umumnya terassosiasi dengan mineral utama. Biji mineral besi misalnya, mengandung logam palladium dalam tingkat renik dan juga terassosiasi dengan logam-logam kelompok platinum lainnya. UU Minerba tahun 2009 melarang industri pertambangan untuk mengekspor bahan mineral dalam bentuk bahan baku (raw material) dan mewajibkan untuk melakukan pengolahan. Di Indonesia sendiri, informasi dan teknik pengolahan/pemungutan serta pemurnian palladium masih sangat terbatas. Metoda pemungutan dan pemurnian yang akan dikembangkan dalam penelitian ini diharapkan dapat diaplikasikan pada tingkat industri. Pemungutan dan pemurnian palladium dengan kisaran konsentrasi ~ 50 g/ton sangatlah memungkinkan untuk dilakukan. Metoda pemungutan palladium dalam hal ini menjadi salah satu penentu nilai ekonomisnya. Oleh karena itu, suatu material fungsional untuk pemungutan palladium akan disintesis dalam penelitian ini. Pemungutan akan dilakukan dengan teknik ekstraksi padat menggunakan material fungsional yang disintesis. Penelitian ini bertujuan untuk mensintesis material fungsional berupa palladium imprinted polimer sebagai kolektor yang dikemas dalam bentuk modul pemungutan palladium yang terkandung dalam biji mineral besi serta optimasi kondisi pemungutannya. Ion-imprinted polimers (IIPs) merupakan fungsionalisasi resin pengkhelat dengan prinsip inklusi molekul kompleks antara pengkhelat dan logam target ke dalam matrik polimer. Logam target selanjutnya dapat dilepaskan untuk memperoleh templat (cetakan) sesuai dengan logam target. Kekakuan (rigidity) struktur templat harus dipertahankan untuk memperoleh selektifitas dan persen pemungutan yang tinggi karenanya molekul kompleks disintesis sebagai komplek terner dan selanjutnya divinilisasi. Pengkondisian molekul dilakukan sebelum polimerisasi untuk mengupayakan kekakuan optimum yang ditunjukkan dari derajat penggelembungan (swelling index) minimum. Kompleks imprinted monomer yang dibentuk dengan interaksi kovalen atau non kovalen, selanjutnya dikopolimerisasi dengan pengikat silang (crosslinker) untuk meningkatkan kemampuan retensi. Polimer dengan crosslinker dan shape selectivity optimum akan mempunyai selektifitas yang lebih tinggi, sehingga mampu memisahkan unsur-unsur dengan sifat kimia dan ukuran ion atau atom yang mirip. Palladium Imprinted Polymer yang diperoleh akan dikarakterisasi dengan scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier transform infra red (FTIR) dan thermal gravimetric analysis (TGA). Pada akhir penelitian ini akan diperoleh material fungsional berupa palladium imprinted polymer sebagai kolektor fasa padat dengan kondisi optimum yang siap diaplikasikan untuk memungut logam palladium dari biji mineral khususnya biji besi sehingga dihasilkan logam palladium dengan tingkat kemurnian >95%.
