Photothermal Deflection Spectroscopy of Collected Aerosols

So why are the detection limits so high forthese photothermal signals? The problem is not one of sensitivity but one of variability Single aerosols can be detected with this apparatus The problem appears to be the irreproducibility of thecollection stage or the aerosols themselves– The MOUDI produces heterogeneous spots– There is an intrinsic variance due to the probabilitydistribution. There may be “chemical” differences in the aerosols usedfor calibration. Laboratory-generated aerosols may not be at equilibrium– Water content may be a large variable