Piezoelectric crystal detectors

Air None (real time) Uncoated piezoelectric crystal detector 0.5 ng No data Kristoff and Guilbault 1983... 

Air None (real time) Coated piezoelectric crystal detector No data No data Milanko et al. 1992... 

Hlavay J, Guilbault GG. 1977. Applications of the piezoelectric crystal detector in analytical chemistry. Anal Chem 49(13) 1890-1898. 

Figure 3.24 — Typical system for piezoelectric crystal detector incorporating reference (C,) and test (CJ crystal sensors individually held in oscillating circuits (Or and 0 respectively) serviced by separate frequency counters (FC, and FCj, respectively) interfaced to a common microprocessor or other readout device. (Reproduced from [167] with permission of the American Chemical Society).

Guilbault, G.G. (1983). Determination of formaldehyde with an enzyme-coated piezoelectric crystal detector, zlwa/. Chem., 55(11) 1682 1684. 

Alpha quartz (low quartz) is most often used for piezoelectric crystal detectors. It crystallizes at temperatures below 573 °C, and transforms to beta quartz (high quartz) between 573 and 870 °C. Generally, AT- and ST-cut quartz plates are used in BAW and SAW, respectively. The term cut designates the direction of the normal to the major faces. A standard AT cut, for example, describes a plate with thickness in the y direction rotated 35° 15 counterclockwise about the X axis (figure 19.1). 

Generally, most of the piezoelectric crystal detectors described in the literature are laboratory prototypes where study conditions are limited to controlled temperature and humidity levels. One of the most serious limitations is non-selective adsorption of analytes, especially water vapor, which is probably the main reason for the current unacceptable performance of the respective detectors... 

PIEZOELECTRIC CRYSTAL DETECTORS FOR ENVIRONMENTAL POLLUTANTS A. A. Suleiman and G. G. Guilbault ... 

The early applications of the piezoelectric crystal detectors were limited to the measurement in the gas phase, because of the common impression that stable oscillation cannot be obtained in the liquid phase. However, recent advances in PZ research have shown that quartz crystals can oscillate in contact with solution, and several studies have been reported addressing the theoretical aspects of the oscillating frequency of piezoelectric crystals in solution. Nomura and Okuhara (92) demonstrated that the frequency change of a crystal immersed in an organic solvent depends on the density and viscosity of the solvent, and was not affected by the dielectric constant ... 

The catalytic effect of bromide on the oxidation of iodine to iodate by permanganate in acidic medium was utilized for the determination of bromide with a piezoelectric crystal detector (99). 

Piezoelectric crystal detectors for environmental pollutants by A.A. Suleiman and G.G. Guilbault 273... 

Figure 4.4.10. Schematic diagram of an isopiestic vapor sorption apparatus using a piezoelectric crystal detector. [Reprinted with permission from Ref 101, Copyright 1995, American Chemical Society].

Suleiman AA, Guilbault GG (1984a) Mercury displacement in the determination of sulfur dioxide with a piezoelectric crystal detector. Anal Chem 56 2964-2966... 

Suleiman A, GuUbault GG (1984b) A coated piezoelectric crystal detector for phosgene. Anal Chim Acta 162 97-102 Tadigadapa S, Mated K (2009) Piezoelectric MEMS sensors state-of-the-art and perspectives. Meas Sci Technol 20 092001-092030... 

Guilbault G.G., Lubrano G., Ngeh J., Jordan J.M. and Foley P. (1986) A protein coated piezoelectric crystal detector, SMCCR-RSB, p. 1-40. 

---