Faeces samples

Procedure. Depending on the diet allocation, weigh an appropriate quantity of the remainder of the marked feed and feed to the specified animal before its normal feed, ensuring all the marked feed has first been consumed. This could be at 21.30 h on the Monday of the collection week. Collect faeces samples 1.5 h before the first feed, then after 8 h, 12 h, and 18 h, and then at 2-h intervals until 01.30 h on Thursday, and at approximately 4-h intervals until 21.30 h Friday. A final sample is taken at 11.30 h on Saturday. 

Faeces samples were obtained from 86 healthy subjects (34 male, 52 female, age 30 8 years) to acquire a wide inter-individual range. All individual stools were collected in their entirety during a period of 5 days in plastic containers. They were weighed and, at the end, homogenised and pooled. Aliquots of stools are lyophilised and then stored frozen at -20°C until analysis. 

The precision of this method was evaluated by repeated analysis of the main human faecal BAs (iso-LCA, LCA, iso-DCA, DCA, CDCA, CA, and 12-oxo-DCA). Within-run precision of ten samples amounted to 4-7% for all BAs. The between-run precision was approximately 5-10% of five time-shifted measurements over 1 month of faeces samples. A standard solution of DCA acetate methyl ester with a DCA concentration of 0.875 mg/ml was added to ten faecal samples of the same origin also used for within-run precision. The mean of concentrations amounted to 1.672 mg/ml, corresponding to a recovery of 94.6%. 

Of crucial importance for the potential risk associated with this contamination of the diet is the question how much of the ingested PCDD/Fs is actually absorbed and retained in the body There is, however, remarkably little information on this subject. There is one report of absorption in an adult man where 87% of a single dose of radioactively labelled 2,3,7,8-Cl4DD dissolved in corn oil was taken up.77 In another study, in which only faeces samples from two individuals on an unmodified diet were analysed, it was found that the excretion rate was very high compared to the theoretical uptake rate,78 which would suggest that absorption is low. No work beyond these two somewhat contradictory studies was found. 

Williams C, David D, lismaa O (1962) The determination of chromic oxide in faeces samples by atomic absorption spectrophotometry. J Agric Sci 59(03) 381-385... 

External decontamination is essential but further assessment including whole-body monitoring may be needed following a risk assessment. Swabs, urine and faeces samples should be taken. Further management is discussed on page 353. 

Feed intake was registered daily and the pigs were weighed weekly, faeces samples for digestibility determination were collected once a day during days 15-18 and stored at -20 °C. Feed and faeces samples were freeze dried and milled through a 1-mm sieve before analysis. 

In the determination of metal ions in animal faeces, digestion with 12% perchloric and 56% nitric acids was in progress when an explosion occurred. This was attributed to one of the samples going to dryness on a sand tray heater. 

Not all faeces were avoided no species significantly avoided the herbivore faeces tested (whiptail wallaby) or the reptilian predator. Their avoidance of mammalian predator faeces, however, suggests that there may be an intrinsic component to such faeces that elicits a response. The novel odour (acetic acid) was never avoided by M. cervinipes and U. caudimaculatus however, R.fuscipes avoided this odour twice, its most consistent avoidance response, which I am at a loss to explain. Quoll faeces (familiar marsupial predator) were avoided on 75% of sampling occasions, the... 

Marin et al. [33] determined the LAS concentration in the faeces of the marine mussel Mytilus galloprovincialis Lmk. The sample was pipetted, dried at 70°C and treated in the same way as sediment samples, referring to Matthijs and De Henau [34], and measured by HPLC with spectroscopic detection. 

In Table 1 the average composition is recorded from two samples of faeces and urine for the net with a mesh size of 0.78 x0.78mm installed on the above mentioned piggery. 

It is not usually possible to measure the concentration of a drug at its sites of action. Plasma, which can be conveniently sampled, is generally used instead, but drug concentrations may be determined in other bodily fluids, such as saliva and cerebrospinal fluid, as well as, of course, the excreta, urine and faeces. There is often a relationship between plasma concentration and response, although this may sometimes... 

Dermal absorption was also studied in rats. [ C]Diethanolamine was applied to 19.5 cm of the dorsal skin (20 mg/cm, 1500 mg/kg bw) and covered for 48 h (no washing) or for 6 h before it was removed by washing. Absorbed [ Qdiethanolamine was determined in 48-h urine and faeces and from sampled tissues. FInwashed rats absorbed 1.4% and washed animals 0.64% of the dose, while the majority of [ C]diethanolamine was recovered in the occlusive wrappings (80%) and in skin of the dose site (3.6%). The radioactivity was found in carcass, liver or kidneys but very little in urine (0.11%), faeces or blood (Waechter etal., 1995, cited by Knaak etal, 1997). 

Megarrity and Siebert [55] have described a method based on AAS for the determination of ruthenium in grass and animal faeces. In this method the sample was ashed at 350 °C with a mixture of potassium nitrate and potassium hydroxide, dissolved in dilute nitric acid and analysed via AA spectrophotometry using a carbon rod atomiser. The method is particularly free from interferences and is suitable for the determination of ruthenium at concentrations of between 5 and 50 xg per gram of dry matter. The atomic adsorption wavelength employed in this study was 349.7 nm. 

FIGURE 20. Thin-layer chromatograms of arsenic in urine, faeces, blood and feed extract Au, authentic compounds A, arsenic acid B, DSMA C, DMAA (X, unknown). Faeces and urine are the second-day samples and blood is the fifth-day sample after treatment of MAF. The asterisk indicates the values in the faeces and blood are As /xg/g of sample weight and in the urine and feed are As g/10 g of sample weight. Reprinted with permission from Reference 178. Copyright (1978) American Chemical Society... 

A variety of in-vitro bioassay samples can be collected from an individual for the purpose of ascertaining whether an internal radionuclide deposition has occurred previously. Samples that may be collected and analysed for such a purpose include urine, faeces, hair, teeth, breath, tissue etc. 

Analysis of herbage (of forage) has sometimes been used to detect and identify radionuclides deposited from the atmosphere (Jackson et al., 1981). However, the problem arises that when the deposition rate is low, large areas of vegetation need to be sampled for detection. In the case of plutonium, an alternative is to collect the faeces of grazing animals such as cows, sheep and rabbits. Plutonium is very poorly absorbed by the mammalian gut and so virtually all that is ingested by an animal will appear in its faeces. Also, if the species selected obtains its food entirely by grazing, then the isotopic ratio Pu will be the same in the faeces as deposited on the... 

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