NDMA - ALS Global

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NDMA as a potential chemical of concern in the Environment. This ... ALS substitutes the more sensitive tandem LC-MS-MS
Environmental Division

ENVIROMAIL # 37

June 2009

N-nitrosodimethylamine (NDMA) in drinking, recycled & catchment water Global studies have increasingly identified the nitrosamine compound NDMA as a potential chemical of concern in the Environment. This increased interest in NDMA and its high toxicity has lead ALS to complete a further research and development project, which now sees testing for this compound possible to extremely low Limits of reporting, typically to 0.003 µg/L or three parts per trillion (ppt). This service is now offered under NATA ALS accreditation. Further information follows. Background on NDMA NDMA (also known as Dimethylnitrosamine or DMN) is a semi-volatile organic chemical of the nitrosamine group that is highly toxic and a probable human Carcinogen. NDMA is extremely soluble in water and is an industrial by-product. Of greatest concern however, is that NDMA can be produced at potentially harmful levels when waste water containing organic nitrogen is subjected to chlorination or chloramination. NDMA can also form or be leached during treatment of water by ion exchange resins. The production of NDMA in the process of recycling waste water for drinking water supplies is therefore of particular interest to stakeholders. NDMA first came to attention as a groundwater contaminant in California in 1998 at several sites that produced rocket fuel. NDMA is found at low levels in numerous items of human consumption including cured meat, fish, beer, and tobacco smoke. The contamination of drinking water by NDMA is particularly problematic due to the trace concentrations at which it is harmful, the difficulty in detecting it at these concentrations, and the difficulty in removing it from drinking water. NDMA does not readily biodegrade, adsorb, or volatilize and given its very small molecular size, it is almost impossible to remove by filtration. Toxicity and Guidelines

ALS - NDMA analysis peak

NDMA (CAS number 62-75-9) is highly toxic and is a documented hepatotoxin that can cause liver tumours in rats at very low doses. The USEPA has determined that admissible concentrations in drinking water are extremely low and as such has set drinking water guidelines limits at 0.007µg/L although some US states have set limits even lower with the 10-6 risk level set as low as 0.003 µg/L.

Right solutions…. ….Right partner

NDMA Chemistry CAS Number: 62-75-9 Molecular Formula: C2H6N2O Method Scope / Suitability The current ALS methodology has been optimised to achieve incredibly low LORs that are likely to be required for Drinking, Desalination, Recycled or Catchment Water Monitoring samples. This test can also be used to monitor groundwater however higher Limits of Reporting (LORs) may apply depending on matrix interference. ALS Method References, Analytical Precision and LORs The ALS methodology is based upon the extraction outlined in USEPA method 521 version 1.0 September, 2004. ALS substitutes the more sensitive tandem LC-MS-MS finish in place of the gas chromatography-chemical ionisation-mass spectrometry used in the original method. The ALS method has a detection limit (MDL) of less than 0.001 µg/L(1ppt) for common matrices and therefore the degree of confidence at the standard LOR of 0.003 µg/L is very high. In addition, lower limits of reporting to less than 0.001 µg/L levels may be available upon request although larger sample volumes will be necessary. The following table summarises analytical performance and accuracy at these incredibly low levels.

Surface Water

Spike Level 0.0050 µg/L

Average Recovery Result 102%

Precision (RSD) 5%

Drinking Water

0.0050 µg/L

109%

6%

Matrix:

Sample Containers and Holding Times ¾ Standard level NDMA analysis requires submission of two x 500mL amber bottles (grey-striped labels) containing 40mg of solid sodium thiosulfate. These must be maintained chilled prior to submission to the laboratory. ¾ For lower level NDMA, 4 x 500ml Amber bottles similarly preserved may be required and it is recommended that LOR needs be discussed with the ALS Technical Manager or relevant Technical staff. ¾ Samples are to be extracted within 7 days of collection and analysed within 40 days.

For further details, please contact ALS Sydney on (02) 8784 8555 or your local ALS Client Services team. References: (1) (2)

NDMA, http://en.wikipedia.org/wiki/N-Nitrosodimethylamine http://www.epa.gov/ncea/iris/subst/0045.htm

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