1. Water in HPLC Under the Supervision of: PROF.DR. Sawsan Elmasry Presented by: Reem Tawfeek

2. Points to be discussed Water used in HPLC. Lab water grades. Specifications of HPLC-grade water. how to determine water purity? Problems caused by poor quality water. Package and storage. Conclusion.

5. Lab Water Grades

6. the different water specifications based on the different water types

7. HPLC-water specifications According to B.P. 2010 water for chromatography is deionized water with a resistivity of not less than 18 MΩ-cm But is this enough It’s possible to have 18 MΩ-cm soup! Can we use soup for HPLC?????

8. How to measure water purity? contaminants in water either

9. Sources of organic contaminants [Total organic carbon(TOC)] Leaching from purification media, tubing and containers, bacterial contamination absorption from the atmosphere

10. Poor quality water reduces chromatographic performance by affecting resolution and integration. introducing ghost peaks. altering stationary phase selectivity. and impacting baselines.

11. Ghost peaks

12. Isocratic baseline monitoring at 210 nm using 100% high TOC reagent water(10 Mᾩ·cm resistivity, 100 ppb TOC) (1 mL/min).

13. Using high-purity water(3 ppb TOC)

14. According to American Society for Testing and Materials ASTM Reagent grade water should contains Total organic carbon (TOC), max , 50 ppb Resistivity not less than 18MΩ-cm

15. Packing and storage packaged in amber glass bottles sealed under a nitrogen with Teflon-lined fluorocarbon caps . Unless other instructions stated by SOP(standard operating procedures) Once the bottle is opened it should be used within 24 hours.

16. Conclusion We should switch from simple resistivity measurement to resistivity and TOC monitoring in order to be able to take reagent water quality for granted.

17. references W.M.A. Niessen, J. Chromatogr., A 856(1,2),179–197 (1999). W. Byrne, Reverse Osmosis — A Practical Guide for Industrial Users. 2nd ed. (Tall Oaks Publishing,Littleton, Colorado, 2002). Standard Specification for Reagent Water American Society for Testing and Materials International 2001 Annual Book of Standards – Volume 11.01 B. Srikanth, Ultrapure Water 15(3), 40–46(1998). K. Clark, M. Retzik, and D. Darbouret, Ultrapure Water 14(2), 21–24, (1997). C. Regnault, I. Kano, D. Darbouret, and S.Mabic,J. Chromatogr., A 1030(1–2), 289–295(2004). B. Stewart and B. Williamson, Am. Biotechnol. Lab., 16–18, December 2001. http://www.high-q.com/pdf/q&a_reagent_water_screen.pdf