Storage bottle, sample

A year-old bottled sample, containing syrupy phosphoric acid as stabiliser and which already showed signs of tar formation, exploded in storage. The pressure explosion appeared to be due to polymerisation, after occlusion of inhibitor in the tar, in a container in which the stopper had become cemented by polymer [1], A similar pressure explosion occurred when dry redistilled nitrile, stabilised with ethanol [2], polymerised after 13 days [3], The spontaneous and violent decomposition of the nitrile on standing for more than a week is usually preceded by formation of a red polymer [4],... 

Bottled samples had been supplied 3 years previously packed in vermiculite in sealed cans. The caps had disintegrated in storage allowing the volatile contents to escape into the external can. When this was pierced, a jet of isocyanate sprayed out uncontrollably. Improved caps are now used for this material [1]. 

Merks and Vlasbom [114] carried out some comparative experiments on standard seawater with potassium hydrogen phthalate and water from Eastern Scheidt and Western Scheidt. These three types of samples were stored in three different ways and in three types of storage bottles. 

Several points need to be considered when applying this pressure method of sample collection. All of the extraction system parts must be explosion proof and the distance from the ceramic cup to the sample bottle must be as short as possible. The sample collection bottle should be at the same level as the ceramic cup. If it is higher, additional vacuum will need to be applied to move the sample water into the sample bottle. Sample storage, once the water is collected, is determined by the analyte of interest. 

PAHs Storage of samples at a temperature of 4°C in amber or foil-wrapped bottles 7 days 113... 

After measuring the sampling volume by weighing the storage bottles, nitric acid should be added (this can also be added before sampling)—1 mL of supra-pure cone. HN03 per 100 mL of precipitation. This will dissolve the metals that could be adsorbed on the walls of the container and will also... 

Losses of metals from dilute aqueous solution on storage are well documented. To prevent this it is usually necessary to acidify the sample after collection and filtration to pH 1. If the sample is to be analysed subsequently by flame AAS hydrochloric acid should be used (Section III.C.2) alternatively, prior to flameless electrothermal atomic absorption analysis, nitric acid should be added to preserve the sample (IV.B). The type of storage container is also important and high-density polyethylene is the preferred material for sample bottles. Here the adsorptive losses of metals appear to be lower than on glass. To avoid container contamination of the sample the container should be leached with dilute nitric acid for several days prior to use. This will remove surface contamination from the container material. Subsequent to the acid-leach, containers are washed in distilled-deionised water and then with a portion of the sample. Storage of samples for mercury analysis requires special conditions and these will be discussed later. 

Surface water samplers can be tested by comparing results obtained on samples collected by the sampling device with those obtained on water aliquots collected directly in the storage bottles, as shown in Table 5.2. The procedure can be applied when filtration can be avoided (particularly when working in open waters). The operation can be carried out by hand and with the use of long polyethylene gloves, in the case of surface waters, or by a plastic telescope bar with the sampling bottle inserted at its end (16). 

Figure 6 Apparatus For Internal Liquid Chromatography. A still collection reservoir or storage bottle, B 3-way valve-inert gas/solvent, C adjustable pump, D 3-way valve-sample injection/solvent, E chromatography column,...

The wine used in this experiment was a 1998 Monastrell red wine from Bodegas San Isidro in Jumilla, Murcia. Table I shows the analytical data of the wine prior to wood aging. All the barrels were filled with the same wine. A control wine was kept in a stainless steel tank. The wines were matured in the oak barrels for six months and stored during one year in the bottle, to meet the specifications for crianza wines. Wine samples were taken after three and six months of oak aging and after one year of bottle storage. Duplicate samples were taken from each barrel. 

A few liters of surface water can be sampled directly with cleaned glass bottles that can also be used for sample storage. For sampling at different depths, Go-flo or Niskin bottles are more suitable, and allow sampling volumes of up to 501. If it is not possible to extract the samples immediately after sampling, these are stored at temperatures below 0°C in stainless steel or glass containers, rinsed beforehand with pesticide grade acetone followed by n-hexane. 

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