AMBER phosphates

Figure 2. Model compounds used to parameterize the AMBER 4.1 force field database. Partial atomic charges for (a) current AMBER phosphate, and (b) new phosphorothioate for inclusion with existing nucleic acids.

The polysulfide base material contains 50—80% of the polyfunctional mercaptan, which is a clear, amber, sympy Hquid polymer with a viscosity at 25°C of 35, 000 Pa-s(= cP), an average mol wt of 4000, a pH range of 6—8, and a ntild, characteristic mercaptan odor. Fillers are added to extend, reinforce, harden, and color the base. They may iaclude siUca, calcium sulfate, ziac oxide, ziac sulfide [1314-98-3] alumina, titanium dioxide [13463-67-7] and calcium carbonate. The high shear strength of the Hquid polymer makes the compositions difficult to mix. The addition of limited amounts of diluents improves the mix without reduciag the set-mbber characteristics unduly, eg, dibutyl phthalate [84-74-2], tricresyl phosphate [1330-78-5], and tributyl citrate [77-94-1]. 

Its composition varies with the animal species and particularly the animal diet. As a result, its color may vary from dark amber to pale, while its pH can vary from 4 to 9. Upon standing, urine gradually throws out CO2 and becomes more alkaline, favoring the precipitation of the dissolved phosphates and organic salts. It is therefore essential that urine samples be buffered to a certain pH prior to analysis, and that the analytical method be validated for a variety of urine samples obtained at different time points from different animals and species. 

Peroxide Substrate Solution Dissolve 25.0 g of anhydrous dibasic sodium phosphate (Na2HP04), or 70.8 g of Na2H-P0412H20, in about 1500 mL of water, and adjust to pH 7.0 0.1 with 85% phosphoric acid. Cautiously add 100 mL of 30% hydrogen peroxide, dilute to 2000 mL in a graduate, and mix. Store in a clean amber bottle, loosely stoppered. The solution is stable for more than 1 week if kept at 5° in a full container. (With freshly prepared substrate, the blank will require about 16 mL of 0.250 N Sodium Thiosulfate. If the blank requires less than 14 mL, the substrate solution is unsuitable and should be prepared fresh again. The sample titration must be between 50% and 80% of that required for the blank.)... 

Funding for this project was provided by the SF Phosphates, Ltd., Rock Springs, Wyoming. We thank Darin Howe and Bill Lew of SF Phosphates for their assistance and help in the project. We also thank Amber Jackson, Maqi Patz, Rachel Shorma, Junran Li, Mary Knight, Kari Fink, and Mary Fortier for their help in plant and soil sampling and laboratory analyses. 

Type Phosphated alcohol Appearance Light amber liquid pH 7.0+-0.5 Characteristic Anionic Weight per Gallon 8.8 lbs. 

Type Modified Phosphated Alcohol Appearance Light Amber Liquid pH 6.3-6.8... 

ELA [Du Pont]. Brand name for elastomer lubricating agent, a mixture of phosphate esters. Light-amber liquid. 

Prepare 30 mM DMAB in 100 mM phosphate buffer, pH 6.5, and store in tightly closed amber bottles at 4 C. 

Each vial contains 5 mg of drug conjugate (protein equivalent) in a 20-mL amber vial. The inactive ingredients are dextran 40, sucrose, sodium chloride, monobasic and dibasic sodium phosphate. Light-sensitive. 

The equilibrium conformations of physical complexes of selected PAHTC s with a dinucleotide fragment of B-DNA have been calculated by the all-atom AMBER empirical force field method [112]. The B-DNA has been represented by the dG2.dC2 dinucleotide fragment. No phosphate groups were placed at the ends of the strands, which instead carried terminal 03 and 05 hydroxyl groups. 

DIchlorvos (DDVP, 2,2-dlchlorovlnyl dimethyl phosphate [CAS 62- 73-7]) An organophosphate-type cholinesterase inhibitor (see p 291), Extremely well absorbed through skin. Evidence of carcinogenicity In test animals (lARC 2B). 0.1 mg/m S, SEN 100 mg/m Colorless to amber liquid with a slight chemical odor. Vapor pressure is 0.032 mm Hg at 32°C (90 F). 

Telraelhyl pyrophosphale (TEPP [CAS 107-49-3]) A potent organo- phosphate cholinesterase inhibitor (see p 291), Rapidly absorbed through skin. 0.05 mg/m , S 5mg/m Colorless to amber liquid wllh a lalnl Irulty odor. Slowly hydrolyzed In water. Vapor pressure Is 1 mm Hg at 140°C (284°F). Not combustible. Thermal-breakdown products Include phosphoric acid mist. 

Uses Flame retardant for rigid and flexible urethane foams, epoxies, laminafes, unsaf. polyesters, plasticized PVC compds., PL) elastomer wire insulation, adhesives, and coatings Properties Amber liq. sol. in Freon 11, polyol, styrene, MEK, triethyl phosphate, methylene chloride, toluene, dioctylphthalate sol. 0.1 g/100 g water sp.gr. 1.95 dens. 16.4 Ib/gal acid no. 0.25 max. 52% Br Great Lakes DE-61 [Great Lakes]... 

Classification Vegetable protein/silicone compd. Definition Polymer of hydrolyzed wheat protein and dimethlcone copolyol phosphate monomers Properties Amber liq. 

Empirical C21H21BO3 Formula (CH3CeH4)3B03 Properties Light amber liq. misc. with acetone, benzene, chloroform dens. 1.065 b.p. 385-395 C flash pt. 115.5 C ref. index 1.5480 (24 C) hydrolyzed by water Precaution Combustible Uses Plasticizer organic synthesis Tricresyl phosphate... 

The complete set of new parameters for the phosphate and phosphorothioate model compounds is given in Table II. The new atom type (SD) and parameters have been added to the AMBER 4.1 force field database for simulating proteins and nucleic acids. For completeness, we have also included a comparison of geometrical parameters taken from optimized model compound structures using the updated AMBER 4.1 force field and HF/6-31G basis set calculations. These values are given in Table III. 

All models were generated with the TLEAP module of the AMBER 4.1 program suite (41) with the Cornell et al. force field (48), using fat sodium ions for the neutralization of the phosphate charges. The 5 -end was modeled without the triphosphate group which is present in the real sample. All structural analysis was carried out with the CARNAL module. 

Figure 1 presents a comparison between the CHARMM run and the AMBER run for the resulting radial distribution functions of the three pairs of charged species in the mlp system sodium-sodium, sodium-phosphorus (as the center of the phosphate... 

Complex Fatty Amido Phosphate Light Amber Liquid Concentration, % 100... 

Alkyl ether phosphate Active % 100 Clear, amber liquid STBPPAC 8170 ... 

Phosphate Ester Form Potassium Salt Appearance Clear, light-amber liquid Actives Content, wt % 50 Specific Gravity at 25C 1.35 Viscosity at 25/25C, cP 40 Density at 25C, Ib/gal 11.2 pH, as-is 8 to 10 Pour Point, ASTM D97, F -10 Flash Point, F 220 TRITON H-66 ... 

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