The CEH Adapted Low-Cost Passive High Absorption (ALPHA) samplers which are used in the UKEAP National Ammonia Monitoring Network, were assessed in a recent study by Puchalski et al. (J. Environ. Monit., 2011, 13, 3156).

Three samplers assessed were assessed: the ALPHA, Radiello(R), and Ogawa passive samplers. The median relative percent differences (MRPD) between the reference method and passive samplers for the ALPHA, Radiello (R) and Ogawa were -2.4%, -37% and -44%, respectively. The precision between duplicate samplers for the ALPHA and Ogawa samplers, was 7% and 6%, respectively.