Detection aerosol

Department of Homeland Security S T-HSARPA Washington, DC, 20528 Ph 202.254.6132 (Keith Ward/Angela Ervin) www.dhs.gov R D, sensors, counter-mine warfare, improvised explosives, airborne surveillance, bio-aerosol detection, container security, and vehicle IED protection. 

Figure 15.5 Instrument schematic of the CAD (charged aerosol detection). (Reproduced...

Tadeusz G, Frederic L, Roman S, Pat S. 2006. Universal response in liquid chromatography using charged aerosol detection. Anal. Chem. 78 3186-3192. 

The physical quality of samples is assessed via analytical methods. Liquid chromatography with mass spectrometry (LC-MS) is the most common instrumentation used to determine sample presence and purity (Kerns et al., 2005). Chemiluminescent nitrogen detection (CLND), charged aerosol detection (CAD) and other techniques have also been used to determine concentration (Popa-Burke et al., 2004 Gamache et al., 2003). 

Gamache, P.H. et al. 2003. HPLC analysis of nonvolatile analytes using charged aerosol detection. LC/GC N. Am. 23, 150-155. 

Choice of the proper detection scheme is dependent on the properties of the analyte. Different types of detectors are available such as ultraviolet (UV), fluorescence, electrochemical, hght scattering, refractive index (RI), flame ionization detection (FID), evaporative light scattering detection (ELSD), corona aerosol detection (CAD), mass spectrometric (MS), NMR, and others. However, the majority of reversed-phase and normal-phase HPLC method development in the pharmaceutical industry is carried out with UV detection. In this section the practical use of UV detection will be discussed. 

Additional detection techniques that can be employed to help solve mass balance issues with RP-HPLC are MS [30], chemiluminescent nitrogen-specihc detector [31], evaporative light-scattering detector, ELSD [32], and corona charged aerosol detection [CAD] [33],... 

The fire sensors are able to detect sodium leakage by two different methods. One is smoke (aerosol) detection and the other is by temperature increase in the room where a sodium fire occurs. Monju already used the former method and this type of sensor will be increased to detect the sodium leakage more quickly and more certainly. The latter method type fire sensors MU be introduced for greater diversity in the detection of the sodium fires. Visual information was found to be useful for operators to know the condition of the room, and so, TV cameras will be installed in the secondary circuit. 

Experience with sodium leaks at our domestic reactors indicates that all leaks without exception, were timely detected. All leaks that occurred on the electrically heated sodium system sections were registered by heaters control systems. In addition, primary sodium leaks were sensed by the radioactive sodium aerosol detection systems. Calculation and experimental analysis of the radioactive sodium aerosol detection system has revealed its high sensitivity and fast response. 

Figure 23-4 Simultaneous separation of anions and cations on a ZIC-HILIC zwitterionic stationary phase with charged aerosol detection. The 150 X 4.6-mm column with S-jim-diameter stationary phase was eluted with a gradient of 20-70% B over 26 min at a flow rate of 0.5 mL/min at 30°C. Solvent A 15 vol% 100 mM ammonium acetate (pH 4.68) in water, 5% methanol, 20% 2-propanol, 60% acetonitrile.

An aerosol detecting agent called DrugAlert can be sprayed on a paper towel that has been used to wipe any household surface to detect a variety of drugs on that surface. 

Detection methods applied in ion chromatography are divided into electrochemical, spectrometric, nebulization, and others. Conductometric, amperometric, and charge detection are electrochemical methods, while the spectrometric methods include UV/Vis, fluorescence, and refractive index detection. In addition, there are various application forms of these detection methods. Nebulization methods include evaporative light scattering (ELS) and charged aerosol detection (CAD). All of these methods are described in detail in this chapter. 

Charged aerosol detection is nonlinear as the amount of analyte being measured depends on the charge that can be placed on the surface of the particle. 

Figure 8.71 Illustration of the power transformation of a polynomial calibration function to a linear one for charged aerosol detection.

Figure 8.73 Signal increase in gradient mode with charged aerosol detection. Separator column Acclaim PA2,2.2 pm column dimensions 50 mm X 2.1 mm i.d. column temperature 45 °C eluent (A) 98 2 (v/v) MeCN/20 mmol/L ammonium acetate (pH 45)...

Figure 8.74 Solvent compensation without a second delay column in an inverse gradient setup for charged aerosol detection.

In addition to formulation analysis, CAD can also be used for other types of ion analysis. Zhang et al. developed a method for the simultaneous determination of 25 inorganic and organic anions and cations that are commonly used as coimterions, using Acclaim Trinity PI (3 pm) and charged aerosol detection [141]. The method is capable of determining the content of sodium, chloride, and fumarate in different drug substances. Limits of detection between 5 ng on coliunn for sodiimi and 400 ng on column for lactate were achieved. 

Figure 8.78 Separation of aii gentamicin sui-fate congeners and reiated substances on a 2.2 pm Acclaim PA2 coiumn with charged aerosol detection. Column dimensions ...

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