The FDA is recommending a second low-temperature test for determining if ranitidine products contain the probable carcinogen N-nitrosodimethylamine (NDMA).

The agency said it is now using a second liquid chromatography-mass spectrometry (LC-MS) testing method that uses a more widely available technology than the agency’s first LC-MS method and it is offering it as an alternative testing option.

The test, which uses a triple quadrupole mass spectrometer (QQQ platform), may be used either as an alternative or as a confirmatory test for the liquid chromatography high resolution mass spectrometry (LC-HRMS) test published in September, the agency said.

The new testing method defines the NDMA limit of detection as 0.3 nanograms per milliliter, or 0.01 parts per million and the limit of quantification as 1.0 ng/mL, or 0.033 ppm.