Isolation high molecular weight organic

Comparison of High Molecular Weight Organic Compounds Isolated from Drinking Water in Five Cities... 

Flodin C, Johansson E, Boren H, Grimvall A, Dahlman O, Morck R (1997) Chlorinated Structures in High Molecular Weight Organic Matter Isolated from Fresh and Decaying Plant Material and Soil. Environ Sci Technol 31 2464... 

In this paper organically-bound sulfur in three types of high-molecular-weight organic matter (kerogen, asphaltenes and resins) obtained from three organic sulfur-rich sedimentary rock samples has been studied. Kerogen, asphaltene and resin fractions were isolated and characterised by the two described techniques. 

When appreciable amounts of pectin, proteins, lipids, unwanted polyphenols, or other compounds are suspected to be present in anthocyanin-containing extracts, some of them can be precipitated or the anthocyanins may be crystalhzed and separated from the others. Pectin and proteins can be removed by organic solvents such as methanol and acetone in order to reduce their solubility, then precipitated and separated by centrifugation. Gelatin was used to remove proanthocyanidin due to its high molecular weight. Anthocyanins were reported to be precipitated early by lead acetate to achieve isolation from other materials. ... 

To aid in the characterization of the DOM pool, marine organic chemists have developed techniques fiar separating compounds into size fractions. Tangential flow ultrafiltration is used to isolate a high-molecular-weight (HMW) fraction from a low-molecular-weight (LMW) fraction. The size cutoff between these is approximately 1 tun, which equates... 

Application of the MAS to drinking water should considerably broaden the scope of organic compounds detected and measured, relative to previously available analytical methods. This conclusion is especially true for the polar compounds of relatively low MW (<500) however, a few of these compounds are not recovered well by the MAS extraction and isolation techniques or are not gas chromatographable, even after derivatization. HPLC methods offer the most promise for separation and analysis of these compounds as well as those of high molecular weight. 

Phenolic extraction of cell lysates is one of the oldest techniques in DNA preparation. Examples of these have been presented in Chapters 6 and 7. Single cells in suspension are lysed with a detergent, and a proteinase enzyme is used to break down the protein molecules. Non-nucleic acid components are then extracted into an organic (phenol-chloroform) solvent, leaving nucleic acids in the aqueous layer. Two volumes of isopropanol are added to the isolated aqueous phase to precipitate the high-molecular-weight nucleic acids as a white mass. These are then treated with DNase-free ribonuclease (RNase) to remove the RNA. This is followed by a second treatment with proteinase, phenol extraction, and isopropanol precipitation. After precipitation, the DNA is separated from the isopropanol by... 

---