Determination of Chloride, Fluoride, Bromide, Nitrate, Sulphate and Phosphate in Water Sample...

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1 I J P F A International Science Press Determination of Chloride, Fluoride, Bromide, Nitrate, Sulphate and Phosphate in Water Sample from Different Area of North Gujarat Region by Ion Chromatography Bharat G. Chaudhary * and Chintu Patel * Abstract: Ion chromatography is the high performance form of ion exchange chromatography. Ion chromatography with suppressed conductometric detection is applicable for the determination of ionic species with high sensitivity, regardless of whether the species are inorganic or organic. In the present research work, ion chromatography with suppressed conductivity detection is used for the determination of fluoride, chloride, nitrate, and sulfate ions in drinking water samples obtain from the different areas of North Gujarat region. The eluent used was 1.7 mmol/l NaHCO 3 and 1.8 mmol/l Na 2 CO 3. Keywords: Inorganic anions, ion chromatography, suppressed conductivity detection. INTRODUCTION Ion chromatography (IC) is the high performance form of ion exchange chromatography. Ion chromatography differs form HPLC in that ion exchange is the primary separation mode and conductivity is the principal method of detection (Jackson and Chassaniol, 2002). In ion chromatography with suppressed conductivity detection, the separator column effluent passes through a suppressor column which chemically reduces the eluent background conductance, while at the same time increasing the electrical conductance of the analyte ions (Small, 2004). This method results in both improved reproducibility and sensitivity when compared to most electrophoretic method of analysis (Connolly and Paull, 2001). The eluents commonly used are NaOH, NaHCO3 and Na2CO3 at various proportions. Ion chromatography offers an easy, fast, small sample volume demanding, and fitfor purpose methodology for the determination of routine ions in surface, ground and potable water samples. Many regulatory and standard organizations, such as ASTM, AOAC, ISO, AWWA, and US EPA, have validated ion chromatographic methods for the analysis of inorganic anions in drinking water. METHODOLOGY Instrumentation and Conditions A Metrohm 883 Basic IC plus with chemically suppressed module, equipped with a Metrosep A Supp 4-250/4.0 column, was used for the ion chromatographic determination of chloride, fluoride, bromide, nitrate, sulphate and phosphate. The instrument was operated with the MagIC Net Basic software and detection was carried out by microprocessor-controlled Digital Signal Processing conductivity detector. The eluent used was 1.7 mmol/ L sodium bicarbonate and 1.8 mmol/l sodium carbonate. The system was optimized to ensure good separation of peaks for all determinants. Chemicals and Reagents Multielement standard contains all six anions (F -, Cl -, Br -, NO, SO 4 ), each at equal concentrations of 10 ppm. (Merck) procured as a gift sample from Metrohm India Ltd., Baroda. AR grades (Merck India Ltd.) sodium carbonate, sodium hydrogen carbonate and sulphuric acid were used. Deionized water having 0.05 µs/cm conductivity (Millipore India pvt.ltd.) was prepared in our laboratory and used during study. 1 Department of Pharmaceutical Chemistry, Shree S. K. Patel College of Pharmaceutical Education and Research, Ganpat University, Kherva , Gujarat, India, bharat_pharmacy@yahoo.co.in I J P F A Vol. 3, No. 1, March

2 Bharat G. Chaudhari and Chintu Patel Preparation of Solutions Mobile Phase Preparation An accurately weighed of 143 mg NaHCO 3 and191 mg Na 2 CO 3 were transferred into 1000 ml volumetric flask and dissolving by adding 500 ml of deionized water. Volume was made up to mark with deionized water while Operating parameters employed for the determination of F -, Cl -, Br -, NO by Ion chromatography with suppressed conductivity detection was given in Table 2. Concentration of various anions in drinking water samples of different area of North Gujarat region was presented in Table 3. Preparation of Regeneration Solution (50mmol/L H 2 SO 4 ) In 1000 ml volumetric flask, 2.7 ml H 2 SO 4 was transferred and volume was made up to mark with deionized water. Standard Stock Solution Standard stock solution of mixed anions was procured as certified solution from Merck contains six anions like F -, Cl -, Br -, NO, SO 4, each having equal concentrations of 10 ppm. Preparation of Working Standard Solutions From the standard stock solution working standards having concentration of 2,5,10 ppm each of (F -, Cl -, Br -, NO ) was prepared by diluting with deionized water. Figure 2: Figure 3: Sample of Modasa, Sabarkantha Sample of Megharaj, Sabarkantha Sampling and Pretreatment Drinking water samples were obtained from different areas of North Gujarat region. Water samples were injected directly with no pretreatment other than filtration through a 0.45 µm filter. RESULTS For calibration purpose working standard solutions of anions were injected. The overlay IC chromatograph of mixed anions standard are shown in Fig. 1. IC chromatographs of drinking water samples from various areas of North Gujarat regions were presented in Fig. 16. The order of elution and retention time for the anions was depicted in Table 1, Figure 4: Figure 5: Sample of Dhansura, Sabarkantha Sample of Bayad, Sabarkantha Figure 1: Overlay of Mixed Anion Standard Figure 6: Sample of Himatnagar, Sabarkantha 2 I J P F A Vol. 3, No. 1, March 2012

3 Figure 7: Sample of Prantij, Sabarkantha Figure 13: Sample of Chanasma, Patan Figure 8: Sample of Mehsana, Mehsana Figure 14: Sample of Harij, Patan Figure 9: Sample of Unjha, Mehsana Figure 15: Sample of Amirghadh, Banaskantha Figure 10: Sample of Vijapur, Mehsana Figure 16: Sample of Palanpur, Banaskantha Figure 11: Sample of Sidhdhpur, Mehsana Figure 12: Sample of Patan, Patan Table 1 Order of Elution and Retention Time for the Anions Analyte Peak number Retention time (min) Flouride Chloride Bromide Nitrate Phosphate Sulphate I J P F A Vol. 3, No. 1, March

4 Bharat G. Chaudhari and Chintu Patel Table 2 Operating Parameters Employed for the Determination of F -, Cl -, Br -, NO by Ion Chromatography with Suppressed Conductivity Detection Parameters Setting / value Column Metrosep A Supp 4-250/4.0 Detection mode foranions Eluent composition Flow-rate of eluent Pressure Analysis time Conductivity 1.7mmol/L NaHCO3and1.8mmol/L Na2CO3.Conductivity after chemicalsuppression approximately14ìs/cm 1 ml/min 4MPa 20min Loop 20µL Suppressorregenerant 50 mm H2SO4, HPLC gradedeionized water. Autostepwith fill Table 3 Concentration of Anions in Drinkimg Water in North Gujarat Region District Taluka Flouride Chloride Nitrate Sulphate (ppm) (ppm) (ppm) (ppm) Sabarkantha Modasa Megharaj Dhansura Bayad Himatnagar Prantij Mehsana Mehsana Unjha Vijapur Sidhdhpur Patan Patan Chanasma Harij Banaskantha Amirghadh Palanpur [1, 2, 3] DISCUSSION Low concentration of fluoride is usually present in drinking water, however higher concentration is often associated with tap water sources. Ion selective electrode and colorimetric method make it possible to measure the total amount of free and complexbound fluoride dissolved in water. Chloride in tap and drinking water originates from both natural and anthropogenic sources. Classical methods generally employed for the determination of chloride in water are silver nitrate titration with chromate indicator and mercury (II) nitrate titration with diphenyl carbazone indicator. The nitrate concentration in drinking water is normally low but as a result of contamination, it can reach high levels. Nitrate in water is determined by using Brucine colorimetric method. In this method nitrate ion reacts with bromine in sulphuric acid at 100ºC to form colored compound whose absorbance is measured spectrophotometrically. Natural and anthropogenic sources are responsible for the presence of sulphate in tap and drinking water. Sulphate in water can be determined by gravimetric method in which sulphate is precipitated as barium sulphate. Turbidimetric method is another method for its determination, in which sulphate ions reacts with barium ions in hydrochloric acid medium to form slightly soluble barium sulphate. The resulting turbidity is measured photometrically. All the above discussed methods for the determination of fluoride, chloride, sulphate and nitrate are time consuming as well as specific for the analysis of particular anions only. In the present research work, all these anions are determined in the water samples by a single injection without any pretreatment step. The total run time for each analysis was 16 minutes. Thus, ion chromatography can be used as a substitute method for the routine analysis of all these anions in water. CONCLUSION According to above result it is concluded that fluoride concentration in north Gujarat region like Modasa, Megharaj, Dhansura, Bayad, Prantij, Unjha, Sidhdhpur, Chanasma, Palanpur, Patan and Amirghadh shown out of limit as per EU s and WHO guideline. Chloride concentration in north Gujarat region like Prantij,Vijapur and Amirghadh shown out of limit as per EU s and WHO guideline. Nitrate concentration in north Gujarat region like Megharaj, Dhansura, Himatnagar, Prantij and Vijapur shown out of limit as per EU s and WHO guideline. Where as in case of sulphate concentration, all north Gujarat regions were with in limit as per EU s and WHO guideline. References [1] Busch, K. W.; Kuehn, A. J.; Busch, M. A.; Yescas, S.; Jimenez, IYG.; Algozo, CM. Determination of Chloride in Aqueous Samples by Isotope-dilution Fourier Transform Flame Infrared Emission (ID-FIRE) Spectrometry. Talanta, 1998, 46, [2] Connolly, D.; Paull, B. Rapid Determination of Nitrate and Nitrite in Drinking Water Samples using Ioninteraction Liquid Chromatography. Analytica Chemica Acta, 2001, 441, I J P F A Vol. 3, No. 1, March 2012

5 [3] Jackson, P. E., Determination of Inorganic Ions in Drinking Water by Ion Chromatography. TrAC Trends in Analytical Chemistry, 2001, 20, [4] Jackson, P. E.; Chassaniol, K. Advances in the Determination of Inorganic Ions in Potable Waters by ion Chromatography. J. Environ. Monit, 2002, 4, [5] Small, H., Ion Chromatography: An Account of its Conception and Early Development. Journal of Chemical. Education, 2004, 81, [6] [7] who-s-drinking-water-standards.htm I J P F A Vol. 3, No. 1, March