I huang cua mpt so vi sinh vat hCru hieu len qua trinh bun hoat tinh xu ly nuac thai ^*^^ bien thuc pham
4. Nguyen Dire Hue (2001) Cdc phuang phdp phdn tich hilu cọ truang DHKHTN-DHQG Hd Noị 5 Pham Hiing Viet (2003) Co sd ly thuyét cua phuong phdp sdc ky khi, NXB Khoa hpc va Ky thuat
5. Pham Hiing Viet (2003). Co sd ly thuyét cua phuong phdp sdc ky khi, NXB Khoa hpc va Ky thuat
Ha Noị
ai Tap chi Phan tich Hoa, Ly va Sinh hoc, 2005
ANALYTICAL DETERMINATION OF REVELANT ALKYLPHENOLS AND BISPHENOL A OF LANDFILL LEACHATES SAMPLES COLLECTED IN HANOIS BISPHENOL A OF LANDFILL LEACHATES SAMPLES COLLECTED IN HANOIS
• * . DUMPING SITES
Tran Thi Tuyet Mai, Tran Thi Lieu, Pham Hung Viet
Research Center for Environmental Technology and Sustainable Development Hanoi University of Science, VNU
ABSTRACT
Some derivative phenols of the alkylphenol group such as nonylphenol, octylphenol and bisphenol A are v^idely present in the envirorunent from industrial and domestic used from the use of medical, diethylstibeltrol, herbisides, pesticides, fungisides. These compound are thought to disrupt endocrine products of alkylphenolethocylates are toxic, persistent in the environment and have the potential to be present in the food chain. This study was focussed on the refinement of an existing technique for the anlysis of alkylphenols and bisphenol A in leachate and ground water samples. The samples were collected from landfill areas in NamSon and TayMo, Hanoị The recovered values of 4-nonylphenol (4-NP), 4-tert-octylphenol (4-t-OP), 4-n-octyophenoI (4-n-OP) and bisphenol A (BPA) were ranged from 84.4 to 91.4%. The results indicated that the concentration of target alkylphenols and bisphenol A in TayMo samples was higher than that of samples from NamSon. The concentrations of 4-NP and BPA in Tay Mo samples was significantly high value in leachates samples, with the concentrations of treated ones were 3913r|g/l and 2026r|g/l for BPA and NP, respectivelỵ And these values were still exceeding the European values of Predicted Non-Effect Concentration for water environment [3]. Il is seemed that in Viet Nam dumping sites are potential pollution sources of alkylphenols and BPA and they have the potential to effect human health and the envirormient.
INTRODUCTION
Nowadays, the identified ECDs can be classified into more than 50 types of groups of chemical such as insecticides, pesticides, fungicides, products of incineration, industrial and domestic wastẹ The analytic procedure of AP and BPA in waste samples is still very difficult because of the complexity of sample matrix. Therefore, to detennine AP and BPA efficiently, the solid-phase micro extraction method (SPME) and Gas chromatograph mass spectrometer (GC-MS) method were applied.
The SPME column with C18 has been chosen in order to separate analysed compounds from the raw sample with high efficiency [3]. Acetic anhydrite is a cost effective solvent to use for the acethyHsation reaction of phenol derivatives.
The purpose of this paper is to optimize the analytical procedure of some APs and BPAs in the groundwater, leachate based on the combination of two tecliniques: SPE and derivitisation ones.
EXPERIMENTAL ANALYSIS
This research include two phases: (1) screenning and optimizing the analytical procedure for APs
and BPAs in rubbish water samples, (2) applying this procedure in the measurement o{ these
compounds in ruooiisira •wmv-i ^^^H^^Â^^ ,^ .re-treated and treated) and surface water samples in Nam Son and Tay Mo landfill areas.
Sampling
Nine leachate samples were collected in amber glass bottles in TayMo and NamSon regions, then filtered through the glass paper in the lab(GF/F, whatman, England). The filtered solution was acidified with HCl 4M to achieve the pH 2 that prevent samples from degrading by microbial organisms, and then stored at 4*^C in the refrigerator until samples are analysed.
Chemicals
The target compounds APs (4-NP, 4-t-OP, 4-n-OP), bis phenol A, internal standard solution naphthlene-d8, bisphenol A-d 14 (surrogate) by Chem Servicẹ
Stock standard solutions of the target compounds were prepared in the acetone(Meck analytical grade) . Then the standard curves of these substance concentrations are established. The samples were denvitised by acetic anhydric. Distilled water used in the laboratory was twice tillered by Milliporẹ
Florisil (90-100 mesh) by Supelco and Na2S04 anhydrous of Merck were baked at 450^^C for 12 hours.
Solid-phase extraction column with the absorbent RP-18500mg by Merck was used.
Equipment
1. SPME (Supelco)
2.GC/MS-QP2010 by Shimazu with spUtless system and detector temperature: 280 C, injection volume is 2|il.
3. Capillary column DB-5 (30m in length, 0.25 mm in diameter and coved by 0.25 f,im of thickness of 100% dimethylpolysiloxane).
Optimization of analytical procedure
lOml volume of sample was taken, then filtered solution of samples was extracted by the SPẸ 200ml of the fillered acid preserved solution was extracted by SPẸ The SPE carridge was twice washed with 20ml hexane, 20nil MeOH and 10ml ion-free water. The sample was pumped into the SPE column with speed of lOml/min (The SPE column was fushed with MeOH to desorb the analytes). The target substances were also desorbed by 20ml MeOH.
10|rl surrogate BPA-dl4 were ađed into the desorbed soUition as accompanying substance, then the yield of recovery was calculated.
The desorbed solution was concentrated by the Rotary, condensed by Nitrogen. The 20ml solution was then dissolved in a mixture Dichloromethane(DCM):hexan (1:3).This mixture is placed on a florisil column(with 5g florisil). This mixture was eluted with 20ml hexan:DCM (2:3) to remove some affector. And a final cultion -ith 100ml (5% MeOH/DCM) to elute AP and BPẠ The extract
The acetylisation reaction was carried by ađing 50pl Pyrol and 50 pl acetic anhydrite into the gas chromaticaly vial. The vial is shaken with the pyrol and acetic anhydride and is left overnight to ensure complete reaction.
The internal standard Naphtalen-d8 10 ppm was ađed into the vial. The solution was brought to 1 ml with hexan and put into the chromatographic vial 1.5 ml, then identified in GC-MS with following program:
The column temperature starts at 50^C for 2 minutes, increases to lOÔC with speed 20"C.min"', then continously to 120°C with the speed lÔC.min"', and finally to 280^^^ with the speed 20°C.min'' for 5 mins. The total time for analysis is 19.5 mins.
RESULTS AND DISCUSSION Optimization of analytical procedure Optimization of analytical procedure
The analytical procedure was optimised using C18 column with SPE due to the case of application, the cost benefit and high efficiency of sepralion of compounds. The technique was further optimised by the acetylisation of phenol by acetic anhydride in pyrol solvent at room
temperaturẹ This two-staged process allows for the accurate and economic analysis oi^
alkylphenol and bisphenol A in leachate sampless.
Using this analytical procedure the result indicates that the recovered efficiency of ankylphenol and BPA is good valuẹ The recover efficiency illustrated in table 1.
Table Ị The recover efficiency of compounds in samples with concentration at 50ng/L
Experiment 1 2 3 4 5 Average Standard deviation Coefficient variation(%) Efficiency (%) 4-NP 39,2 41,6 42,7 47,5 46,1 43,4 1,69 3,88 86,8 tert-OP 42,8 41,9 38,5 45,1 42,6 42,2 1,12 2,82 84,4 n-OP 41,8 46,5 42,6 44,5 39,6 43,0 1,37 3.19 86,0 BPA 47,9 49,1 42,7 47.2 41,8 45,7 1,54 3.37 91.4 BPA-dl4 92.5 89.4 91,6 86,8 87.3 89.5 1,26 1.41 89.5
These efficiency values are relatively high. Hence, this anal>'tical procedure ensure the accurancy and the requirement for analysis.