PRCs performance reference

Huckins, J.N. Petty, J.D. Lebo, J.A. Almeida, F.V. Booij, K. Alvarez, D.A. Cranor, W.L. Clark, R.C. Mogensen, B.B. 2002b, Development of the permeability/performance reference compound (PRC) approach for in situ calibration of semipermeable membrane devices (SPMDs). Environ. Sci. Technol. 36 85-91. 

In order to assess an analyte s in situ SPMD-water exchange kinetics, performance reference compounds (PRCs as described in Chapter 1) are added to SPMD triolein prior to an exposure (Ellis et al., 1995 Booij et al., 1998 Ockenden et al., 2001 Huckins et al., 2002a). To use this approach, the investigator must be... 

Huckins, J.N. 1998, Effect of deployment devices on performance reference compounds (PRCs) loss. USGS Columbia Environmental Research Center Columbia, MO Unpublished work. 

The performance of SPMDs, which implies longer exposition and so higher risk of losses of PAHs during sampling, needs to be evaluated too. It results advisable to use reference compounds to validate them, the so-called performance reference compounds (PRCs) for SPMDs. These standards act like RS, but are only referred to the sampling stage. 

The utilization of internal standards (IS), recovery standards (RS), and performance reference compoimds (PRCs) for SPMDs, described in air monitoring, is also applicable to water samples. 

Then, the effectiveness of the ADS/PRC method in promoting the dispersion of the supported phase and consequently the reactivity of FeOx/Si02 system in MPO, has been evaluated by comparing the performance of catalysts prepared using either Si 4-5P or F5 silica carriers by INC/WET and ADS/PRC methods, respectively. Activity data at 650°C of the various catalysts in the MPO reaction, with reference to Si 4-5P and F5 silica carriers, are presented in Table 2 in terms of hourly CH4 conversion (Xch4,h, %), product selectivity (Sx, %) and reaction rate (rate, pmolcH4 s "g ), while the relative space time... 

---