Fitri  Oktafiani, Rizky  Stiyabudi, Wahyu  Hendra Gunawan, Mitrayana  , 
    CO<sub>2</sub> Laser Photoacoustic for Measuring NH<sub>3</sub> Gas Concentration on Exhaled Breath of Scavengers on Landfill,
    Journal of Engineering and Applied Sciences,
    Volume 12,Issue 14,
    2017,
    Pages 3687-3691,
    ISSN 1816-949x,
    jeasci.2017.3687.3691,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2017.3687.3691)
    Abstract: A CO<sub>2</sub> laser photoacoustic spectrometer intracavity configuration has been built and tested. The
application was for determining the NH<sub>3</sub> gas concentration on exhaled breath of scavengers on the Landfill. The 
off-line experiment was conducted through non-invasive sample method using exhaled breath. Exhaled breath
sample was taken by three daily variations of the morning, mid-day and post-day. The data was analized by
multicompound gas method using the software of excel, origin and scilab. The result from the photoacoustic
spectrometer intracavity configuration with the strongest frequency resonance(1650&plusmn;5) Hz at biomarker gas
occured on absorption lines 10R14, 10P14 and 10P16. The lowest detection boundary from ammonia is
(23.3&plusmn;0.5) ppbV. The highest ammonia concentration from scavengers was (2904&plusmn;1) ppbV occured in the early
morning and the lowest concentration was (1089&plusmn;1) ppbV in the post-day. Meanwhile, on healthy volunteers,
the highest ammonia concentration was (1676&plusmn;1) ppbV in the morning and the lowest ammonia concentration
was 377&plusmn;1) ppbV in the mid-day. It shows the contamination of air ambien caused the increasing concentration
of biomarker gas in the human body.
    Keywords: Spectro meter;scavengers;photoacoustic;occured;concentration