Chemical samplers

NDRC scientists measured the travel of the war gases by concentric circles of automatic chemical samplers. Military personnel staked out goats on a grid of their own. The goat detail was handled by the old-time chemical warfare Major. After one large test, there was a discrepancy between the results of the chemical analyses and the location of dead goats. 

Dosage, D, is defined as the product of gas concentration in air multiplied by the time an animal or person is exposed to the concentration. The chemical samplers drew in outside air at a steady known rate for a known time and extracted the mustard gas from the air. The total amount of mustard gas in the sample gave dosage at the location of the sampler. Also, there were other sampling devices in use. 

Samplers must be designed and constmcted to withstand the chemical composition extremes present in the individual discharges. 

Personal sampler A collection device attached to a person that obtains samples of air to be tested for radioactive, chemical, or biological agents. 

POCIS Oolar organic chemical integrative samplers... 

Samples were processed in clean rooms in the shore laboratory within 30 min of sampling. Results indicated (i) the feasibility of inter-calibrating using the enclosure approach (ii) the availability of chemical techniques of sufficient precision in the case of copper, nickel, lead, and cobalt for sampler intercomparison and storage tests and (iii) a problem in sub-sampling from the captured seawater in a sampler, and the difficulty of commonly used samplers to sample seawater in an uncontaminated way at the desired depth. 

A second strategy relies on parallel experimentation. In this case, the same experimental step is performed over n samples in n separated vessels at the same time. Robotic equipment such as automated liquid-handlers, multi-well reactors and auto-samplers for the analysis are used to perform the repetitive tasks in parallel. This automated equipment often works in a serial fashion as, for example, a liquid handler with a single dispensing syringe filling the wells of a microtiter plate, one after another. However, the chemical formation of the catalyst or the catalytic reaction are run at the same time, assuming that their rate is slow compared to the time needed to add all the components. The whole process appears parallel for the human user whose intervention is reduced. 

M256-Series Chemical Agent Detector Kit A kit used by military personnel to detect and identify field concentrations of nerve, blister or blood agent vapors. The kit consists of twelve samplers/detectors and a packet of M8 detector paper. It is used at the squad, crew or section level to detect and identify field concentrations of nerve, blister or blood agents vapors. It is usually used to determine when it is safe to unmask, to locate and identify chemical hazards, and to monitor decontamination effectiveness. 

M272 Water Testing Kit A lightweight portable kit used to detect and identify dangerous levels of common chemical warfare agents in raw and treated water in about seven minutes. It is a test water sampler and is not a continuous monitor. Each kit includes twenty-five tests for each agent. 

Automated injectors are often used when large numbers of samples are to be run. Most designs involve the use of the loop injector coupled to a robotic needle that draws the samples from vials arranged in a carousel-type auto-sampler. Some designs even allow sample preparation schemes such as extraction and derivatization (chemical reactions) to occur prior to injection. 

Major components of dissolution equipment are the tester (including typically, but not limited to, spindle assemblies, belt, motor, tension adjuster, and circulator pump and hoses), water bath, paddles, baskets and shafts, vessels, samplers, and analyzers. Mechanical aspects, such as media temperature, paddle or basket speed, shaft centering and wobble, and vibration can all have a significant impact on the dissolution of the product. Mechanical and chemical calibration should therefore be conducted periodically, usually every 6 months, to ensure that the equipment is working properly. 

More recently, Harner et al. (2003) coated ethylene vinyl acetate (EVA) onto glass (polymer coated glass [POG]) for use as fugacity sensors or equilibrium samplers of SVOCs in indoor and outdoor air. The EVA film fhickness was 1.1 and 2.4 qm depending on the application and as expected, SVOC sorption capacity and times to equilibrium were shown to be directly proportional to film thickness. The clearance capacity Ey volume of sample medium cleared of chemical) of a sorbent for an analyte is given by... 

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