Agilent Announces Technique for Measuring Ultralow and High Concentration Elements in Drinking Water

Agilent Technologies Inc. announced a new procedure that is the first to enable simultaneous measurement of ultralow and high concentration elements in drinking water. The new method can assist regulatory agencies and municipal water suppliers in meeting stated public health goals (PHGs) for the presence of certain chemicals.

The recent debate over federal arsenic standards in the United States highlighted the need for accurate, precise measurement of toxic compounds at the lowest practical limits. More recently, the California Office of Environmental Health Hazard Assessment (OEHHA) released a draft PHG for arsenic of 4 ppt (parts per trillion), a level 2,500 times lower than the current enforced standard of 10 ppb (parts per billion). This discrepancy exists because PHGs are based solely on stringent health considerations and, therefore, often exceed the detection limits of available chemical analysis techniques.

Agilent's method can detect element concentrations such as arsenic in the low ppt range, enabling government officials to set more rigorous drinking water standards that better protect public health. The new method also solves the challenge of analyzing ultratrace levels such as mercury at 5 ppt or less, as well as very high analyte concentrations such as sodium as high as 1,000 ppm (parts per million) in one run, without creating false positives from polyatomic interferences or out-of-range elements. No other single analytical technique can overcome this hurdle.

The method uses the Agilent 7500c ICP-MS with Octopole Reaction System (ORS) to simultaneously detect very low and very high analyte concentrations. The ORS incorporates collision/reaction cell technology to eliminate polyatomic interferences on critical regulated elements. The result is sub-ppb detection limits for nearly all elements of interest. It also allows the analyst to use passive collisions in the ORS to reduce the ion current for high-concentration, low mass elements. The dynamic range for these elements is shifted upward to allow accurate, linear measurement at levels previously impossible by ICP-MS.

Further information is available by requesting Agilent application note "Meeting Worldwide Regulatory Requirements for the Analysis of Trace Metals in Drinking Water Using the Agilent 7500c ICP-MS," Agilent publication number 5988-8902EN. This note is available without charge from any Agilent sales office or Agilent's website at www.agilent.com/chem.

Source: Agilent Technologies