By Dr. Maria Ofitserova

Increasing Awareness of Nitrosamines Contamination in Water and Pharmaceuticals

Nitrosamines are a class of compounds that are considered human carcinogens and mutagenic agents. These compounds can be formed in the presence of amines and nitrosating agents and are found in water, food, cosmetics and personal care products as well as pharmaceuticals.

Contamination of drinking, ground or waste waters with Nitrosamines is due to either industrial sources or formation during sanitation process that uses chloramine. A number of states have published regulatory guidelines for levels of Nitrosamines in drinking and ground waters ranging from 0.017 to 0.0007 ppb

In cosmetics, the compound most often found as contamination is N-nitrosodiethanolamine (NDELA). The FDA monitors and reports the presence of Nitrosamines in cosmetics sold in the United States.  Nitrosamines impurities are also covered in Annex II and Annex III of the European Cosmetics Directive (76/768/EEC), which establishes the regulatory limits at 50 ppb for maximum content of Nitrosamines.

Recent identification of alarming levels of Nitrosamines in a number of prescription and over-the-counter medications has led to recalls as well as permanent removal of certain products from the market. In February 2021, FDA published the guidelines for the pharmaceutical industry to control Nitrosamines impurities in human drugs. The guidelines direct manufacturers of Active Pharmaceutical Ingredients (API) and finished pharmaceuticals to detect and prevent unacceptable levels of Nitrosamines contamination. The FDA guidelines also establish Acceptable Intake (AI) limits for Nitrosamines impurities.

Analyzing Nitrosamines at the contamination levels established for water, cosmetics and drugs requires highly sensitive analytical methods. High Performance Liquid Chromatography coupled with post-column photolysis and chemiluminescence detection has been used to analyze Nitrosamines in water samples without pre-concentration at levels below 1 ng/L. Determination of NDELA in cosmetics according to ISO/DIS 10130 is also performed using HPLC with post-column photolysis and chemical derivatization, followed by UV/Vis or fluorescent detection.  

Pickering Laboratories, Inc. supplies laboratories with the UVE^TM photochemical reactor, which is ideally suited for in-line photolysis and can be easily coupled with any HPLC system for analysis of Nitrosamines in water or pharmaceuticals. Combining UVE^TM with the Onyx PCX derivatization system would allow laboratories to additionally implement method ISO/DIS 10130 for analysis of NDELA in cosmetics and personal care products.