Microgram per gram

What is the concentration of copper, in micrograms per gram FFDT, for a 11.23-mg FFDT tissue sample that yields an absorbance of 0.023 ... 

Calibration of an arc or spark source is linear over three orders of magnitude, and detection limits are good, often within the region of a few micrograms per gram for elements such as vanadium, aluminum, silicon, and phosphorus. Furthermore, the nature of the matrix material composing the bulk of the sample appears to have little effect on the accuracy of measurement. 

Environmental Levels and Exposures. Barium constitutes about 0.04% of the earth s cmst (47). Agricultural soils contain Ba " in the range of several micrograms per gram. The Environmental Protection Agency, under the Safe Drinking Water Act, has set a limit for barium of 1 mg/L for municipal waters in the United States. 

Impurity levels reported as micrograms per gram of sample. 

You may also be exposed to endrin by eating foods that contain endrin. Before cancellation of endrin use, reported concentrations of endrin in domestic and imported food samples ranged from 0.05 to 0.50 parts per million (ppm where 1 ppm = 1 microgram per gram (pg/g) of food). However, no endrin was detected in food samples from a Texas survey and only 0.084% of over 13,000 food samples were found to contain endrin in 1989 after cancellation of endrin use. 

As an example, Table 4.3.1 presents the results calculated from reversed-phase and normal-phase HPLC analysis, respectively, of samples taken from an industrial WWTP [16]. Concentrations were expressed in microgram per gram of material as received. In the water sample, reversed-phase HPLC analysis showed the presence of NP and NPEO (Fig. 4.3.7(A)) with levels of 0.008 and 0.383 p,gg 1 (sum of NPEO), respectively. Normal-phase analysis of NPEO oligomers... 

A withdrawal time is the time from the last availability of a medicated feed to an animal until its slaughter. This time is set so that the level of residues drops below the lower level of detectability of the antibiotic and is based on a tissue residue study in which animals are dosed with the highest level of drug in the feed for the longest time permitted. The method of analysis must be sufficiently sensitive to detect fractions of a microgram per gram in tissue. 

This chapter provides some insight into the chemistry of a number of commonly used polymeric sorbents. Particular focus is placed on the chemical identification of contaminants typically associated with each of the following types of polymeric sorbents Amberlite XAD resins, Ambersorb XE resins, and PUF. Emphasis is placed on the chemical speciation of solvent-extractable organic contaminants present in a number of these sorbents as received from the manufacturer. Both qualitative and quantitative data on a micrograms-per-gram (parts-per-million) basis are provided as determined by combined gas chromatography-mass spectrometry (GC-MS). 

The results of these analyses are summarized in Table I. The estimated amounts of each compound are given in terms of micrograms per gram of dry resin. In a normal resin separation-concentration procedure, these amounts would be the same, independent of the amount of water passed through the resin. Some peaks could not be identified. 

Straight lines drawn through the calibration points could then be used to find the concentrations of theobromine and caffeine in an unknown. From the equation of the theobromine line in Figure 0-7, we can say that if the observed peak height of theobromine from an unknown solution is 15.0 cm, then the concentration is 76.y micrograms per gram of solution. 

Food yeast, molasses-grown, is dried to about 5% moisture and has the same chemical composition as bakers yeast. In terms of micrograms per gram of yeast, the vitamin content is 165 thiamine 100 riboflavin 590 niacin 20 pyridoxine 13 folacin 100 pantothenic acid 0.6 biotin 160 para-ainiiiobeuzoie acid 2710 choline and 3000 inositol. YeasL crude protein contains 80% amino acids 12% nucleic acids and 8% ammonia. The latter components lower the true protein content to 40% of the dry cell weight. 

A wide variety of sample types, sample preparations, and processes have been used. Powdered rock samples were fused with K2B07 or K2C03, followed by precipitation of the potassium using perchloric acid, separation with methanol-perchloric acid, evaporation to a residue, and dissolution of the residue in dilute nitric acid. Detection limits in the solid were in the microgram per gram ( xg/g) to nanogram per gram (ng/g) levels in the solid without preconcentration. 

Calculation If a computer-based instrument is used, the data output is reported as micrograms per liter. Calculate the concentration of arsenic, in micrograms per gram (equivalent to milligrams per kilogram), in the original sample taken by the formula... 

Micro equipment is required. With concentrations of only a few micrograms per gram in the fish tissues, it is seldom practicable to use samples containing more than 40-50 /xgrams of a single pesticide. All the work reported here was carried out with a 1.5-mm. micro KBr pellet in a Perkin-Elmer model 421 infrared spectrophotometer, equipped with... 

Note.- All concentrations are reported as micrograms per gram (ppm) except chromium and iron, which are reported as weight percent. 

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