In the US, the Environmental Protection Agency (EPA) has set a preliminary public health goal (PHG) of 1 part per billion (ppb) for perchlorate in water. Agilent and Metrohm's new method can detect perchlorate at levels below 100 parts per trillion in drinking or surface water, allowing regulators and testing laboratories to reliably and easily identify water supplies that approach or exceed the PHG level.
According to the EPA, there have been confirmed perchlorate releases in at least 20 US states. The California Department of Health Services reports that perchlorate has been detected in more than 350 water sources in California alone.
"This method provides regulatory agencies and laboratories with a powerful tool to identify and quantify perchlorate contamination and address potential health risks," said Mike McMullen, vice president and general manager of Agilent's Chemical Analysis Solutions unit. "The Agilent/Metrohm method is simple and reliable and does not require expensive or complex instrumentation. The combination of Agilent's and Metrohm's leading technologies will help customers meet regulatory demands for lower detection limits."
The technology is of special interest to the brewing industry, which is highly regulated when it comes to the safety of its water supply.
The Agilent/Metrohm method uses ion chromatography and mass spectrometry (IC/MS), combining the Metrohm Advanced Ion Chromatograph and Agilent 1100 Series mass selective detector as an affordable solution for environmental analysis. This application was developed as part of a co-marketing agreement between the two companies.
The new method is claimed to have several advantages over conventional perchlorate detection techniques, which rely on ion chromatography with conductivity detection. Typical methods can measure perchlorate only at 1 to 5 ppb in drinking water, and the sensitivity decreases dramatically as sample complexity increases. Interference by other ions in the sample can cause false positive and false negative results. In addition, reproducibility when analysing heavy matrix samples such as river water or wastewater is poor.
"By using relatively simple parameters and robust instrumentation, the Agilent/Metrohm method effectively reduces ion interference and eliminates many of the sensitivity and reproducibility problems seen with other methods," said Helwig Schaefer, vice president of Metrohm. "This clearly illustrates the feasibility and effectiveness of coupling IC and MS for this and other environmental applications."