Light protection

Up to 52 wt % is permitted to be shipped in uv light-protected polyethylene dmms. Double headed aluminum dmms are permitted for 70% shipments but have not been used for some years. 

Considering the low stability of the pigments, all manipulations should be carried out in a light-protected environment. Equipment and glassware should be covered with black cloth or aluminum foil low temperatures for evaporation in the rotary evaporator or evaporation of small volumes directly under N2 or Ar should be used. Acidic pH should be avoided. Solutions and extracts should be stored at low temperatures under inert atmosphere and all procedures should be carried out as quickly as possible. 

Besides these "physical aspects" of the light protection of polymers there are some hints that UV-stabilizers of the o-hydroxyphenyl-benzotriazole type are able to scavenge radicals ("chemical aspects") the production of which could not be suppressed completely by the methods described in this paper (23). 

NFPA requirements state that if equipment or process vessels, columns of tanks are suitably constructed of substantial steel construction adequately grounded, and do not give off flammable vapors, no other mechanism of lighting protection is required. This is also true of flares, vent stacks and metal chimneys by nature of their construction and grounding facilities. 

National Fire Protection Association (NFPA), NFPA 780. Lighting Protection Code. NFPA, Quincy, MA, 1992. 

Drying lo-bromo-p-chloroacetophenone oxime was carried out in the dark since otherwise this material turns pink in light. Wrapping the flask with )luminum foil provides adequate light protection for this purpose. 

Labeling requirements in 58.105(c) are not controversial and are the minimum to ensure against mix-up of test or control articles. The Expiration date needs to be included on the label only if one has been established. Some laboratories include a retest date on the label as a reminder of the need for periodic stability analyses. Only special storage conditions (e.g., refrigerate, protect from light, protect from freezing ) need to be included on the label. 

Native urine should be protected from light and stored at -20°C until processed. Oxidized urine sample can be stored at room temperature, but light protection is still recommended. Two procedures for the oxidation of urine (and other samples) are used (1) oxidation with manganese dioxide (Mn02) under acidic conditions, and (2) oxidation with iodine (iodine/potassium iodide, I2/KI) under acidic and basic conditions. The Mn02 oxidation method is a routine method used to quantify total pterins (fully oxidized neopterin, monapterin, biopterin, primapterin, isoxanthopterin, and pterin) the I2/KI method is used according to Fukushima and Nixon [11] for the differential oxidation of pterins and quantification of BH4. Total biopterin represents the sum of BH4, BH2, and fully oxidized biopterin. Under acidic conditions BH4 and BH2 are oxidized to biopterin, while under basic conditions only BH2 is oxidized to... 

Porphyrin acid marker kit (10 nmol of each uro-, heptacarboxy-, hexacarboxy-, pentacarboxy-, coproporphyrin, all I-isomers) solubilized in 5 ml 3 M HC1 (stable at 4°C and light-protected for 2 weeks). 500 pi of this solution are further diluted 1 4... 

H.J. Heller and H.R. Blathmann, Some aspects of light protection of polymers . Pure A Appl. Chem., 30, 1972, 145. 

In the initial studies, as briefly described earlier, the methyl a-2-thioglycoside of Neu5Ac 5 [22,24], or the -1 1 anomeric mixture 11 [26,27], which can be almost quantitatively prepared from 9 in one step, was coupled with lightly protected sugar acceptors such as 14,16, and 18 in the presence of DMTST in acetonitrile to give exclusively the sialyl a(2—>3)- or sialyl ot(2—>6)-D-galactose or lactose derivatives (20, 22, and 24) in 50-70% yields even in large-scale reactions [26],... 

Injection blow molding of polycarbonates produces an assortment of containers from 20-L water bottles and 0.25-L milk bottles to outdoor lighting protective globes. 

Store proanthocyanidins in a light-protected container at -20°C or cooler. 

Recovery of Polymer. After polymerization the latex was coagulated by adding methanol (with 1% phenyl-/J-naphthylamine (PBNA)). The precipitate was washed with methanol (in which 1% PBNA was dissolved), vacuum dried at low temperature, and kept under vacuum in a light-protected vessel. 

They carried this reaction out under pseudo-first-order conditions (excess of 2-nitro-propanate ions) in acetonitrile at 25°C, under argon atmosphere in a light-protecting vessel. The 2-nitropropanate ion was introduced as the tetramethylammonium salt. Two products were formed (Scheme 8-10). One of the products was the expected C-substituted compound. The other was an unstable species, which decomposed into the 4-nitrocumyl alcohol during workup and was ascribed to O-substitution. In 1975, Komblum had obtained the same products. He considered the C-substitution as an SRN1 reaction and the O-substi-... 

Davidson SW, Lyall D. Sodium nitroprusside stability in light-protected administration sets. Pharm J 1987 239 599-600. 

Incubate the slide in a humidified chamber with light protection at room temperature for 30 min. 

Based on ESR signal strength of a light-protected, sealed sample. 

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