Container head space

The objective in packaging cool sterilized products is to maintain the product under aseptic conditions, to sterilize the container and its Hd, and to place the product into the container and seal it without contamination. Contamination of the head space between the product and closure is avoided by the use of superheated steam, maintaining a high internal pressure, spraying the container surface with a bactericide such as chlorine, irradiation with a bactericidal lamp, or filling the space with an inert sterile gas such as nitrogen. 

Both solvent-extracted and expelled coffee oils can be sprayed directly onto soluble coffee solids. The oil is adsorbed without degradation, provided moisture and oxygen are absent. However, the most volatile compounds do tend to leave the coffee powder and fill the head space of the container. 

The moist sulfide readily oxidises in air exothermally, and may reach incandescence. Grinding in a mortar hastens this [1]. The impure sulfide formed when steel processing equipment is used with materials containing hydrogen sulfide or volatile sulfur compounds is pyrophoric, and has caused many fires and explosions when such equipment is opened without effective purging. Various methods of purging are discussed [2], Formation of pyrophoric FeS in bitumen tanks is considered as a cause of spontaneous ignition and explosion in the head space [3], A detailed study of formation of possibly pyrophoric sulphides from rust in crude oil tankers has been made [4],... 

Structure elucidation of the female-produced sex pheromones of Trogo-derma spp. has a rather confused history. Extracts of females of T. inclusum were shown to contain (Z)-14-methyl-8-hexadecenol and the methyl ester of the respective carboxylic acid [215]. The corresponding compounds showing (E)-configuration were shown to be present and behaviourally active in T. inclusum [216]. Finally, investigations of head space collections, obtained with live females, revealed the presence of 14-methyl-8-hexadecenal, an aldehyde... 

In order to characterise the components further, mass spectral analysis was carried out. When head space volatiles from undigested cow slurry were analysed on a non-polar column the results (Figure 5) demonstrated the presence of several sulphur containing compounds—methanethiol, carbon disulphide, dimethyl sulphide, 2-propanethiol,... 

A final reaction volume of 250 pL, containing 2.6 pyi YqjM (corresponds to approximately 0.1 mg mL total protein content), 25 him EDTA, 100 pu FMN, 1 him ketoi-sophorone and 50 mM tris-HCl (pH 7.4), was incubated under anaerobic conditions (closed reaction vessel with small head space) at 30 °C in a water bath exposed to the light of a 100 W Osram white-light bulb for 4 h. The experimental semp was the same as described in Procedure 2 (Section 10.2.2). 

Ion mobility spectrometry (IMS [43]). Solid phase microextraction (SPME) using a 100 pm polydimethylsiloxane (PDMS) SPME fibre was used for head-space sampling and preconcentration of volatile markers of cocaine, MDMA and marijuana (methyl benzoate, piperonal and terpenes, respectively) in cargo containers. Analysis was then performed by IMS after thermal desorption of the drug markers from the fibre into the IMS analyser. 

Oxidation can be best minimized by replacing the air in the head space of the final product container with an inert gas such as nitrogen, and/or the addition of antioxidants to the final product. 

Collect the test solution in a tight container with minimal head-space, and test in a timely manner to minimize the impact of organic contamination from the closure and container. 

Figure 3.8 Conceptualization of the potential functions in a hydrostatic system and in a simple chemical system, (a) In the unequilibrated hydrostatic system, water will flow from reservoir 2 of higher hydrostatic potential (=gh2, where g is the acceleration due to gravity and h2 is the observable height of water in the tank) to reservoir 1 of lower hydrostatic potential total water volumes (i.e., total potential energies W [ and W2) do not dictate flow. Similarly, benzene molecules move from liquid benzene to the head space in the nonequilibrated chemical system, not because there are more molecules in the flask containing the liquid, but because the molecules initially exhibit a higher chemical potential in the liquid than in the gas. (b) At equilibrium, the hydrostatic system is characterized by equal hydrostatic potentials in both reservoirs (not equal water volumes) and the chemical system reflects equal chemical potentials in both flasks (not equal benzene concentrations).

Container Capacities, Fill Point Variation, Sterile Filter Monitoring, Start-Up Checks. These all can be checked easily on a statistical basis. The frequency of each check should be specified so that these become routine functions of quality control. Filler-bowl wine temperature fluctuations are extremely important since they may be a major cause of fill-point fluctuation in bottles. This fluctuation cannot be overemphasized because of legal ramifications. Specific standards of fill and head-space maxima are listed by the Bureau of Alcohol, Tobacco and Firearms in 27 CFR, part 4. 

It takes -1 hr to run a blank, and another hour to run the alkane standards by direct head-space sampling (see Basic Protocol 1). With OV-101 and similar substrates, these standards need be run only once every day or two. With more polar and less stable substrates, or with samples that contain a lot of nonvolatile material, the standards and blanks need to be run more often. In the worst case, these must be run... 

One major advantage of the package is that it contains no head-space because the top seal is actually formed through a column of sterile product. This lack of headspace offers some protection, at least initially, to oxygen-sensitive products. 

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