PREPARATION AND CHARACTERIZATION ION SELECTIVE LECTRODE Cd(lI) BASED ON CHITOSAN IN PVC MEMBRANE

Preparation of the c hitosan membrane of ion-selective electrode for determination of cadmium ion has been conducted. Chitosan is a natural polymer containing nitrogen could coordinate with CcP to increase the membrane conductivity v alue. Chitosan is a principal material and mixed with polyvinylchloride (PVC) as matrix dissolved previously to solvent tetrahydrofuran (THF) and dioctylphenylphosphonate (DOPP) is added as plasticizer by proportion chitosan: PVC: DOPP (6:3:1). To obtain the dopant optimum concentration, membrane was dipped in Cd²&#8314for 7 days and its conductivity value was measured using the four-point probe method. From FT-IR spectrum the peaks of amine, acetylamide and hydroxy groups wave length number was observed to assure that Cd ²&#8314bound to the chitosan. The optimum concentration of Cd²&#8314dopant was obtained at 1.00 M with conductivity value of 549.45 ohm-1m-1 wich gave a Nernstian factor of 32.03 mV/decade with the detection limit of 2.512 x 10 &#8208&#8309M. The electrodes work in the pH range 3 - 7. The life time of the electrode was 8 weeks. The ions of N²&#8314, Fe³&#8314, Pb²&#8314, CU²&#8314, Zn²&#8314,CR and S0&#8324²&#713toward concentrationrange 10&#713³M gave response did not interfere in the determine of Cd²&#8314ion

INTEGRATED GAS-LIQUID SEPARATOR-REACTOR FOR DETERMINATIONSn(lI) AT TRACE LEVELS IN SOLUTION Reaktor Separator Gas-Cair Terintegrasi untuk Penentuan Sn(lI) pada Level Renik dalam Larutan

ABSTRACT The determination of Sn(lI) 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 gasliquid separator at various sizes was able to increase sensitivity in the determination of Sn(lI) in solution. The acid reagent mixing techniques, sample and reductant optimally occurs in a coil reaction before they are going to the gasliquid separators. The optimum conditions of parameter measurementin the determinationof 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 J.lgCI for 100J.lLinjection volume (3.74 pg Sn). The accuracy of measurementshown 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. Keywords: Sn, hydride generation, gas-liquid reactor separator, QFAA

PREPARATION AND CHARACTERIZATION ION SELECTIVE ELECTRODE Cd(II) BASED ON CHITOSAN IN PVC MEMBRANE

Preparation of the chitosan membrane of ion-selective electrode for determination of cadmium ion has been conducted. Chitosan is a natural polymer containing nitrogen could coordinate with Cd2+ to increase the membrane conductivity value. Chitosan is a principal material and mixed with polyvinylchloride (PVC) as matrix dissolved previously to solvent tetrahydrofuran (THF) and dioctylphenylphosphonate (DOPP) is added as plasticizer by proportion chitosan:PVC:DOPP (6:3:1). To obtain the dopant optimum concentration, membrane was dipped in Cd2+ for 7 days and its conductivity value was measured using the four-point probe method. From FT-IR spectrum the peaks of amine, acetylamide and hydroxy groups wavelength number was observed to assure that Cd2+ bound to the chitosan. The optimum concentration of Cd2+ dopant was obtained at 1.00 M with conductivity value of 549.45 ohm-1m-1 wich gave a Nernstian factor of 32.03 mV/decade with the detection limit of 2.512 x 10-5 M. The electrodes work in the pH range 3 - 7. The life time of the electrode was 8 weeks. The ions of Ni2+, Fe3+, Pb2+, Cu2+, Zn2+, Cl- and SO42- toward concentration range 10-3 M gave response did not interfere in the determine of Cd2+ ion

Ion-pair reversed-phase chromatography for speciation of organotin compounds

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 (k’) 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

MODIFIED GAS-LIQUID SEPARATOR FOR THE DETERMINATION OF Sn(II) WITH HYDRIDE GENERATION-QUARTZ FURNACE FLAME â?? ATOMIC ABSORPTION SPECTROPHOTOMETRY (HG-QFAAS)

The performance of determination of Sn(II) ion with hydride generation-quartz furnace atomic absorption spectrophotometry (HG-QFAAS) has been studied, by modifying the gas-liquid separator used. This modified gas-liquid separator at various sizes was able to increase sensitivity in the determination of Sn(II) in liquids. It has been determined that separators perform best at tube lengths of 9 cm and tube diameters of 3 cm, in which the mixing techniques reagent of acid, sample and reductant occur in a coil before going to the gas-liquid separators. The analytical performance in this method is good, which is shown by detection limit 3.74 &m

INTEGRATED GAS-LIQUID SEPARATOR-REACTOR FOR DETERMINATION Sn(II) AT TRACE LEVELS IN SOLUTION

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.   Keywords: Sn, hydride generation, gas-liquid reactor separator, QFAA