Sample bag

Gas collectors A sampling bag used to collect a sample for analysis. 

Sample bag A. bag made from an inert polymer such as Teflon, complete with a fitting for connecting to an air-sampling pump. 

Additionally, a good scraping tool, such as a putty knife or wide-blade screwdriver, plus a small hammer, deposit sample bags, and a camera (if allowed) are also required. 

To avoid contamination of the samples, the sampling equipment should be free from contaminants and a sampling bag must be used to protect the samples from contamination. 

Plot numbers and sampling dates are recorded on the sampling bag. 

Samples of odorous air for olfactometric analysis are usually collected into a sample bag and transported to a laboratory for analysis. A sample bag may be placed in a container, and the bag is gradually filled with odorous air when air is removed from the gap between the container and the bag using a vacuum pump. 

The membrane produces a semi-sealed unit that enables waste reagents to be contained after use (waste bag fills as sample bag empties). 

Hcxanc can be determined in biological fluids and tissues and breath using a variety of analytical methods. Representative methods are summarized in Table 6-1. Most methods utilize gas chromatographic (GC) techniques for determination of -hexane. The three methods used for preparation of biological fluids and tissues for analysis are solvent extraction, direct aqueous injection, and headspace extraction. Breath samples are usually collected on adsorbent traps or in sampling bags or canisters prior to analysis by GC. 

Avoid anything plastic, including para-film and plastic sample bags. If zip-loc sample bags are used, then wrap the sample in aluminum foil first. 

In order to prevent condensations, an equipment is used, dynamically allowing the dilution of a known flow of the odorous gas in a known flow of an inodorous gas the temperature of the dilution gas must be that of the gas to be diluted if it is a hot gas ideally a heat exchanger should be set as much upstream the olfactometer (or sampling bag) as possible. 

The largest problem turned out to be the temperature differences between outlet air (85-220 C) and outdoor temperatures (0-15 C), causing condensation. The dew point of the outlet air was calculated, and experiments were carried out with dilution of the outlet air to prevent condensation in the sampling bags. Condensation was prevented by diluting the outlet air 5-150 times with diy, purified N2 gas. 

The TO 6 type got two separate gas jet pumps, one for each measuring range and an el. magn valve. A range selector does the same as the flow selector of the modified TO 4 type. The second stream is lead to an additional sniffing port which can be used by the panel leader. A port selector brings the main stream to one of four sniffing ports (masks), installed in four separate boxes. This equipment has been set up in a caravan. To set it vertical it is mounted to a ball and socket. Four panelists can take place in front of their masks A sample bag can directly be connected to the olfactometer. The delay between... 

The caravan is equiped with an own propan gas operated electric power unit and the ventilation system is equiped with activated carbon filters to get an odourless athmosphere guaranteed. After arriving at a farm it takes less than five minutes to prepare the system for the first measurement. With a team of four well-trained panelists and three repetitions it takes only about six minutes per sample. Inclusive necessary breaks for the panelists and for changing the sample bags six measurements per hour are possible, but not more than about 20 samples per day. 

An empty 30 litre sample bag with a stainless steel pipe will be put into the container. The pipe is pushed through the cover. A PTFE tube will be fixed to the pipe to collect samples from different points. On the transparent cover a batteiy operated vacuum cleaner and a battery are mounted. Only by pressing a push button the sample is filled in about 10 seconds. By using this sampling device sampling doesn t make any problems. 

The recommended standard method evolved is therefore as follows. The apparatus consists of flowmeters, two 1 1 glass cylinders in series and an odour sampling bag of Tedlar , connected with PTFE tubing as shown in Fig. 1. The air used is oil- and odour-free and preferably from a compressed air cylinder. The air stream splits in two so that the diy air mixes with the humid air that has passed through the sludge, so as to prevent condensation in the odour sampling bag. 

Exhaled air Collection of whole breath into a sampling bag collected sample pulled through a Tenax cartridge GC/Electrolytic conductivity 13 ng on cartridge 63 13 Joetal. 1990 > z > 1 K H... 

Two final examples of the sensitivity and general applicability of the FTIR gas analysis technique are illustrated in Fig. 8. Trace (A) shows the spectrum obtained from an ultra-air filled 70 liter sampling bag into which had been injected, 18 hours previously, 4.8 microliters of TDI, toluene diisocyanate. On the basis of the single feature at 2273 cm l, it is estimated that 50 ppb TDI could be detected. The lower Trace (B), shows the spectrum of nickel carbonyl. This highly toxic but unstable gas was found to decay rapidly at ppm concentrations in ultra air (50% lifetime 15 minutes). Calibration of its spectrum was established by recording successive spectra at ten minute intervals and by attributing the increase in carbon monoxide concentration (calibration known) to an equivalent but four times slower decrease in nickel carbonyl concentration. The spectrum shown represents 0.6 ppm of the material. Note the extraordinary absorption strength. The detection limit is thus less than 10 ppb. 

Araki A, Noguchi T, Kato F, et al Improved method for mutagenicity testing of gaseous compounds by using a gas sampling bag. Mutat Res 307(l) 335-44, 1994... 

Road materials were gathered from 9 locations on unpaved roads in the vicinity of the sampling site. At each location, dust from the roadbed was scraped into a polyethylene sample bag from 5 or more spots over a 10 m area. These materials were also air dried and sieved Identically to the soil materials, but not crushed. Visual inspections of the road surface suggested that samples from 8 of the 9 sites were primarily crushed limestone rock. The remaining site consisted primarily of washed gravel derived from glacial deposits. An inventory of unpaved road surface materials within 5 km of the sampling site indicated that approximately 80% consisted of crushed limestone. 

However, if one applies the heterogeneous kinetics reported by Takagi et al. (1986), one can calculate that methyl nitrite concentrations of the order measured in the exhaust sample could arise by reactions of unburned methanol and N02 on the walls of the sampling bag prior to analysis (Finlayson-Pitts et al., 1992). 

Refractometer with automatic temperature compensation feature Stomacher lab blender with sample bags (Fisher)... 

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