Groups formulae

Parlar et al. [58] described a novel approach to quantitation of chlorodecanes using low resolution GC-ECNIMS. They synthesized specific C10-PCAs (Cl4 to Cl6) and used characteristic ions of each formula group to quantify components in cod liver oil. Because of the difficulty of separating PCAs even on high resolution GC columns, Parlar et al. [58] recommended the use of direct introduction into the mass spectrometer via a short uncoated column. Other authors... 

Generation of formula group abundance profiles allowed PCA concentrations to be reported according to individual formula and homologue groups yielding much more detailed information on the extent of transformation of PCAs in environmental samples as well as previously uncharacterized proportions of these groups in commercial products. 

Fig. 2. Formula group abundance profiles of a C10-C13 commercial PCA mixture containing 60 mass % Cl (PCA-60) [14]. Each bar represents the relative proportion of each group in total PCAs...

Fig. 3. Chlorinated n-alkane formula group profiles for beluga whales (Delphinapterus leu-cas) from Cumberland Sound, western Hudson Bay, the southeastern Beaufort Sea, and the St. Lawrence river estuary are compared with a commercial short chain chlorinated paraffin with 60% chlorine (PCA-60). The arctic beluga show higher proportions of the lower chlorinated congeners (C15-C17) compared with the commercial product and the St Lawrence River animals. Results from Tomy et al. [78]...

Fig. 4. GC-ECNI high resolution mass spectrometry selected ion chromatograms of the C10H15C17 formula group, based on the [M-Cl] ion, for beluga blubber samples from Cumberland Sound and Hudson Bay are compared with an extract of an air sample from Alert (NWT) at the northern tip of Ellesmere Island and in the PCA-60 standard. The air sample shows a strong resemblance to the commercial product while the profile in beluga suggests considerable biotransformation. Results from Tomy et al. [78]...

An international inter-laboratory study highlighted the importance of using external standards whose formula group profile closely resembles that of the... 

Perhaps the biggest advantage to generating formula group profiles is that it enables the fate and behavior of individual formula groups of CPs to be monitored. For example, Houde et al. (2008) were able to examine the trophic transfer and biomagnification of individual formula groups of CPs in two aquatic food webs in Canada [23]. 

The expanded formula shows each atom and bond. One type of condensed formula groups each C atom with its H atoms. Carbon-skeleton formulas show only carbon-carbon bonds and appear as zig-zag lines, often with branches. Each end or bend of a zig-zag line or branch represents a C atom attached to the number of H atoms that gives it a total of four bonds ... 

If the mother decided to start bottlefeeding, the infant was randomly assigned to one of two hydrolyzed protein formula groups (plus 0.8 g/100 ml pre-biotics or maltodextrine as placebo). 

Clinical studies in term (Camielli et al. 1996, Kennedy et al. 1999, Lopez-Lopez et al. 2001) and preterm infants (Camielli et al. 1995, Lucas et al. 1997) have demonstrated the correlation between the level of palmitic in the sn2 position on fatty acids and calcium absorption. The reduction in calcium and fatty acid absorption is accompanied by increased calcium soaps and, consequently, hard stools (Quinlan et al. 1995). Infants receiving the high sn2 formula had softer stools and fewer formed and hard stools than did control regular vegetable oil formula group (Sidnell and Greenstreet 2011, Kennedy et al. 1999, Litmanovitz et al. 2014, and Yao et al. 2014). 

Molecular formula (group of Isomers) Trivial name Number of Isomers log Kow Solubility In water at 25 °C (mg/l)... 

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