The effect of sodium chloride concentration on the assay of LAS in seawater by MBAS methods
Kartal Çetintürk, Kasım Cemal Güven
Institute of Marine Science and Management, Istanbul University, 34470, Vefa, Istanbul, TURKEY
Present address: TUDAV (Turkish Marine Research Foundation) Beykoz, Istanbul, TURKEY
The effect of salinity in seawater on methylene blue active substance (MBAS) method for LAS determination was investigated. To reproduce the salinity of the Black Sea (18 ‰), Sea of Marmara (24 ‰) and Mediterranean Sea (34 ‰), we used sodium chloride from Aegean Sea, Merck and Baker products. Standard curve of LAS was drown in seawater reproduced in the same salinity. It was found that the purity and concentration of sodium chloride have an effect on the LAS level determined by Standard Methods in sample tested. Merck and Baker sodium chloride give similar results but using common salts, the results are more reliable.
In this work we proposed a modification improve MBAS assay in seawater as follows:
1. Standard LAS solution must be prepared with common salts with the same concentration as seawater tested.
2. The blank chloroform used was prepared applying the procedure of calibration curve of LAS determination by MBAS method omitting LAS.
3. The extraction with chloroform was made 6 times instead of 3 times.
4. The calibration curve of LAS was plotted using common salts instead of distilled water, with the same salinity of seawater examined.
5. Correlation equation were calculated from the equations of different salinity of seawater (18, 24, 34 ‰).
Keywords: LAS, sodium chloride, MBAS method
Akıncı, S. and Güven, K. C. (1997). A new determination method of anionic detergent in the seawater based on metachromasy and correlation between AzurA and methylene blue assays. Turkish J. Mar. Sci. 3: 191-198.
Bektaş, A. and Güven, K. C. (2004). Determination of LAS by metachromatic method in seawater and reservoir water. Acta Pharm. Turc. 46: 83-94.
Crisp, P. T., Eckert, J. M. and Gibson, A. (1978). The determination of anionic detergents at p.p.b. levels by graphite furnace atomic absorption spectrometry. Analytica Chimica Acta 87: 97-101.
González-Mazo, E. and Gómez-Parra, A. (1996). Monitoring anionic surfactants (LAS) and their intermediate degradation products in the marine environment. Trends in Analytical Chemistry 15: 375-380.
Güven, K. C., Gürakın, N., Akıncı, S. , Bektaş, A. and Öz, V. (1994). Metachromatic method for the assay of LAS in town and sea water. Acta Pharm. Turc. 36: 136-140.
Hellman, H. (1979). Analytische Bestimmung von Aniontensiden in Schweb- und Sinktoffen sowie Klarschlammen. Analytische Chemie 295: 393-397.
Hon-Nami, H. and Hanya, T. (1978). Gas-liquid chromatographic-mass spectrometric determination of alkylbenzenesulphonates in river water. J. chromatog. 161: 205-202.
Hon-Nami, H. and Hanya, T. (1980). Linear alkylbenzene sulfonates in river and bay water. Water Research 14: 1251-1256.
Koç, H., Gezgin, K.C. (2002). Toxicity and identification of LAS in tissue of rainbow trout (Oncorhynchus mykiss). Turkish J. Mar. Sci. 8: 197-208.
Koç, H., Güven, K.C. and Gezgin, T. (2002). Degradation of LAS in distilled, tap and seawater. Turkish J. Mar. Sci. 8: 91-102.
Marcomini, A., Capri, S. and Giger, W. (1987). Determination of linear alkylbenzenesulphonates, alkylphenol polyethoxylates and nonylphenol in waste water by high-performance liquid chromatography after enrichment on octadecylsilica. J. Chromatogr. 403: 243-252.
Raymundo, C. C. and Preston, M. R. (1992). The distribution of linear alkylbenzenes in coastal and estuarine sediments of the western North Sea. Mar. Poll. Bull. 24:138-146.
Scott, M. J. and Jones, M. N. (2000). The biodegradation of surfactans in the environment. Biochim. Biophys. Acta. 15: 235-251.
Srivastava, V.K., Misra, B.B. and Tripathi, A.M. (1977). Effect of acid and inorganic salts on metachromasia induced by hetropolyanions. Transition Met. Chem. 2: 106-108.
Standard Methods (1995). American Public Health Ars. New York 14 th.
Terzic, S. and Ahel, M. (1993). Determination of linear alkylbenzene sulphonates in the Krka River estuary. Bull. Environ. Contam. Toxicol. 50: 241-246.
Terzic, S., Hršak, D. and Ahel, M. (1992). Enrichment and isolation of linear alkylbenzenesulphonate (LAS) degrading bacteria from estuarine and coastal waters. Mar. Poll. Bull. 24: 199-204.