Cytotoxicity assays


Cd(OH) j. The hydroxide is precipitated from aqueous solution by OH", it does not dissolve in excess OH". Ignition of Cd(OH)2 or CdCO, gives CdO which varies in colour from red-brown to black because of lattice defects.  [c.74]

The use of Lamb waves offers the possibility of rapid long-range in-service inspection. Receiver and transmitter probes are positioned single sided - access is only required from one side of the specimen - in a pitch-catch-arrangement, the receiver being outside tbe field of the specular reflection.  [c.845]

The methyl benzoate is removed by extraction with chloroform, and upon cautious acidification of the aqueous layer perbenzoic acid is liberated the latter is extracted with chloroform and is usually preserved as a solution in this solvent  [c.807]

Paper coatings are appHed as coatiag colors, which are aqueous slurries containing 35—65 wt % soHds. There are three maia components of the soHds pigments, biaders, and minor additives. The pigment is the primary component of a paper coatiag and consists of small, white, particulate material. Pigments usually are minerals, eg, clay, calcium carbonate, or titanium dioxide. The packed pigment particles fiU pitted areas of the rough paper surface, thereby providing a suitable surface for printing. Biaders are the resias or polymers that fuactioa as the glue that biads the pigment particles to each other and to the paper substrate. The level of biader is low ia a paper coatiag, typically 5—30 parts by weight per 100 parts of pigment. This low level of biader distiaguishes paper coatiags from paiats, which are pigment-filled polymer films. Minor additives are used to modify the properties of the coatiag color, primarily before and duting the coatiag operatioa.  [c.22]

Finishes. Fiber finishes are designed to provide fiber cohesion, lubricity, and static-free operabiHty at low and high traverse speeds over a variety of metallic and ceramic surfaces encountered in fiber plant and mill operations (134—136). Fiber cohesion is important in that loose or protmding filaments can catch on processing equipment and cause snags and breaks, or become entrapped within a windup package, causing uneveimess in texturing, knitting, and weaving. Finishes, consisting primarily of lubricants, emulsifiers, and antistatic agents, are generally appHed as aqueous emulsions at concentrations giving a finish-on-yam level of 0.3—1% after the evaporation of water. Lubricants can consist of mineral, vegetable, and animal oils or waxes (triglycerides), or of such synthetic types as esters, polyethers, siHcones, and ethoxylated esters. Depending on lubricant compatibiHty, the degree of fiber wettiag desired, and the required oil—water balance, emulsifiers can be anionic (eg, sulfated vegetable oil), cationic (eg, quaternary ammonium compounds), nonionic (polyglycols), or amphoteric (eg, betaines). Finish antistats fall iato the same categories. Other functional chemicals, such as biocides, antioxidants, dyeiag assists, and mbber adhesion promoters for tire manufacturiag, are added on an as-needed basis.  [c.256]

In the laboratory, sodium is best handled in a glove box filled with nitrogen or another inert gas, or in a water-free hood. When sodium is handled on the bench top, water and aqueous solutions must be excluded from the area. Tools for cutting or handling sodium must be clean and dry. Contact of sodium with air should be kept to a minimum because moisture in the air reacts rapidly with sodium. A metal catch pan under the equipment is essential to  [c.168]

Calcium chloride meeting Food Chemicals Codex (ECC), specifications is used as a direct and indirect food additive. Chemical specifications for anhydrous calcium chloride include assay, not less than 93.0% arsenic (as As), <3 ppm fluoride, <0.004% heavy metals (as Pb), <0.002% lead, <10 ppm magnesium and alkaU salts, <5% acid insoluble matter, <0.02% and no particles of sample greater than 2 mm in any dimension. Each agency includes methods of sampling, testing, packaging, and shipping within the specifications. Additionally, The American Concrete Institute (ACl) specifies the uses of calcium chloride for its members (20—23).  [c.415]

The synthetic pigment is produced by one of several related procedures. The best quahty product is made by reaction of an aqueous solution of CdSO or CdCl with a solution of an alkaline metal sulfide or H2S. Zn, Se, or Hg may be added to the CdS to produce shade vatiations. After precipitation, the color is filtered, washed, and calcined in an inert atmosphere at 500—600°C.  [c.428]

For commercial Ephedra the British Pharmaceutical Codex, 1934, specifies a total alkaloidal content of not less than 1-25 per cent, when assayed by the method therein prescribed. The proportion of Z-ephedrine is generally about 70 per cent. Methods of assay for total alkaloids are described by Feng and Read and by Krishna and Chose, who discuss the various difficulties involved and comments on these and other methods have been made by various workers. Conditions affecting the results of such assays have also been discussed by T ang and Wang, and Brownlee has shown that chloroform is not a suitable medium for the assay since it converts ephedrine quickly and 0-ephedrine slowly to the hydrochloride.  [c.636]

For each quality objective you should have a plan that defines the processes involved in its achievement. Assess these processes and determine where critical decisions are made and who is assigned to make them. Audit the decisions and ascertain whether they were contrary to the objectives. A simple example is where you have an objective of decreasing dependence upon inspection. By examining corrective actions taken to prevent recurrence of nonconformities you can detect whether a person decided to increase the level of inspection in order to catch the nonconformities or considered alternatives. Any person found making such a decision has clearly not understood the quality objective.  [c.149]

For example, in aqueous solution ASt = AS + 8.0 cal mol K thus, it is advisable to be cautious in making mechanistic inferences based on the magnitude  [c.255]

To the solution of phenyldiazonium chloride add a solution of 36 g, of potassium iodide in 40 ml. of water slowly and with shaking. Nitrogen is evolved. Allow the mixture to stand for a few hours. Fit the flask with an air condenser (5) and heat it cautiously in a boiling water bath until evolution of gas ceases. Allow to cool. Decant as much as possible of the upper aqueous layer and render the residual aqueous and organic layers alkaline by the cautious addition of 10 per cent, sodium hydroxide solution, t.c., until a drop of the well-shaken mixture withdrawn on a glass rod imparts a blue colour to red litmus paper. The alkali converts any phenol present into sodium phenoxide, which, unlike phenol itself, is not volatile in steam. Immediately transfer the mixture to a steam distillation apparatus (Fig. II, 40, 1) and steam distil until no more oily drops pass over. Transfer the distillate to a separatory funnel and run oflF the lower layer of iodobenzene into a small conical flask. The crude iodo-benzene should have a pale yellow colour if it is dark in colour, return it to the separatory funnel and shake it with a little sodium bisulphite solution until a pale yellow colour is obtained, then remove the heavy layer as before. Dry with about 1 g. of anhydrous calcium chloride or anhydrous magnesium sulphate filter through a fluted filter paper into a small distilling flask equipped with a short air condenser (Fig. II, 13, 2). Distil using an asbestos-centred wire gauze or, better, an air bath (Fig. 11,5, 3) and collect the fraction b.p. 185-190° (6). The yield of iodobenzene (an almost colourless liquid) is 33 g. the compound gradually develops a yellow colour upon exposure to light.  [c.599]

The experimental conditions for the reduction are similar to those for the Grignard reaction. For compounds which are readily soluble in ether, a solution of the compound in dry ether is added to an ethereal solution of lithium aluminium hydride (excess) at such a rate that the reaction mixture boils gently. When the reduction is complete, the excess of the reagent is decomposed by the cautious addition of moist ether, an ethanol-ether mixture or by the dropwise addition of cold water with vigorous stirring when water is used, it is desirable to employ a large flask because of the foaming which takes pleice. On the whole it is best to employ ethyl acetate, as its reduction product (ethanol) does not interfere in the subsequent isolation and no hydrogen is evolved. The reaction mixture is then poured gradually into excess of ice-cold dilute sulphuric acid to decompose the complex aluminium compounds and to dissolve the precipitated aluminium hydroxide the product is usually in the ethereal layer but, if it is water-soluble, must be isolat from the aqueous solution. For bases, after extraction of any neutral or acidic products, the solution is rendered alkaline with ION sodium hydroxide and the whole (including the precipitated aluminium hydroxide) is extracted with ether. For compounds which are slightly or sparingly soluble in ether, a Soxhlet apparatus is inserted between the flask and the reflux condenser and the compound is placed in the Soxhlet  [c.878]

The slow stream of nitrogen through the apparatus prevented the THF from being sucked back from the cold trap. When refluxing had ceased, the contents of the trap (a solution of ethane and propyne in THF) were cautiously poured into the dropping funnel and subsequently it was added in a few minutes to the reaction mixture. The condenser was again connected with the empty trap and stirring was continued for another 1 h. The conversion of propyne took (from the moment of addition) aoout 3 h and for hexyne and trimethylsilylacetylene 1-2 h. The solutions of the acetylenic Grignard compounds were cooled to 10°C, 3 g of CuBr were added and, after stirring for 10 min at about 10°C, the temperature was lowered to 0°C. Propargyl tosylate (see Chapter Vlll-3, Exp. 3, for a general procedure for tosylates) (0.47 mol) was added in 10 min at 0°C (a cooling bath of dry-ice and acetone is required). The reaction mixture was kept for 30 min between 0 and 5°C, and subsequently for 1 h between 10 and 15°C. When R = n-C H9 or Me3Si the reaction mixtures were hydrolysed by cautious addition of 200 ml of a solution containing 50 g of NH Cl and 7 g of NaCN or KCN. After vigorous stirring the upper layers were separated and the aqueous layers were extracted three times with diethyl ether. The combined solutions were dried over magnesium sulfate. Most of the solvent was distilled off at normal pressure through a 40-cm Vigreux column  [c.72]

Anhydrous liquid ammonia (2 1) was transferred from a cylinder into the reaction flask. Sodium (47 g) was introduced in pieces of 1-2 g. Ten minutes after the addition of the sodium, dimethyl disulfide (commercially availabe) was added dropwise from a dropping funnel with a long stem. The reaction was very vigorous and addition of anmonia to maintain the volume of the reaction mixture at 2 1, was necessary. The addition of dimethyl disulphide, which took 30 min, was stopped as soon as the blue colour of the sodium had disappeared slightly more than 1 mol appeared to be required. Propargyl chloride (2.0 mol) was subsequently added in 40 min to the vigorously agitated mixture. Ammonia was added to bring the volume of the mixture at 1.5 1. Twenty minutes after the addition of propargyl chloride a solution of 0.3 mol of sodium ethoxide in 150 ml of liquid anmonia was cautiously poured into the reaction mixture. This solution had been prepared in a 500-ml round-bottomed flask by cautious addition of 0.4 mol of absolute ethanol to 0.3 mol of sodium in liquid ammonia. Stirring was continued for 1 h after the addition of sodium ethoxide. A rubber stopper with a narrow hole was placed on the flask and the ammonia was allowed to evaporate. To the remaining salty mass was added 1 1 of water and, after dissolution of the salt, the upper layer was separated as sharply as possible. The aqueous layer was extracted twice with 50-ml portions of pentane. The organic layer and the pentane extracts were separately dried over a small amount of magnesium sulfate. After practically all pentane had been distilled off from the extract at normal pressure (using a 40-cm Vigreux column), the remaining liquid and the first organic fraction were combined and distilled  [c.107]

A solution of methylmagnesiurn bromide in 600 ml of THF, prepared from 1.30 mol of methyl bromide (see Chapter II, Exp. 7) was added dropwise over a period of 45 min. During the addition the temperature of the mixture was at first kept between -20 and -10°C and towards the end between 0 and +5°C (note 1). Ten minutes after addition of the Grignard solution, 260 ml of high-boiling light petroleum (b.p. > 170°C) were added, then the salt slurry was cautiously poured into 500 ml of 2 N hydrochloric acid, pre-cooled to about -10 C. The remaining salt in the flask was dissolved by cautious addition of 2 N HCl. The upper layer was shaken twelve times with 250-ml portions of 2 N HCl and the combined aqueous layers were extracted once with 100 ml of light petroleum, the organic layer being washed eight times with lOO-ml portions of 2 N HCl. The light petroleum solutions were combined and dried over magnesium sulfate. The dried extract was gradually warmed in a distillation apparatus (consisting of a 500-ml round-bottomed flask, 40-cm Vigreux column, condenser and receiver, cooled at -75°C, see Fig. 5) which was evacuated by means of the water pump (10-20 mmHg). Between the water pump and the receiver was placed a tube filled with kOH pellets. Evacuation and heating were stopped as soon as the light petroleum began to reflux in the top of the column. The receiver contained a 70 30 mixture of 2,3-pentadiene and isopropylacetylene, yield about 65%. Extremely careful fractionation (preferably through a spinning band column)  [c.160]

Analytical Procedures. Standard methods for analysis of food-grade adipic acid are described ia the Food Chemicals Codex (see Refs, ia Table 8). Classical methods are used for assay (titration), trace metals (As, heavy metals as Pb), and total ash. Water is determined by Kad-Fisher titration of a methanol solution of the acid. Determination of color ia methanol solution (APHA, Hazen equivalent, max. 10), as well as iron and other metals, are also described elsewhere (175). Other analyses frequendy are required for resia-grade acid. For example, hydrolyzable nitrogen (NH, amides, nitriles, etc) is determined by distillation of ammonia from an alkaline solution. Reducible nitrogen (nitrates and nitroorganics) may then be determined by adding DeVarda s alloy and continuing the distillation. Hydrocarbon oil contaminants may be determined by ir analysis of halocarbon extracts of alkaline solutions of the acid.  [c.246]

Gelatin is identified by a positive test for hydroxyproline [51-35-4] turbidity with tannic acid [1401-55-4] or a yeUow precipitate with acidic potassium dichromate [7778-50-9] or trinitrophenol [88-89-1]. A 5% aqueous solution exhibits reversible gel-to-sol formation between 10 and 60°C. Gelatin gives a positive color test for aldehydes and sugars that are considered undesirable impurities in photographic gelatin nucleic acids are considered restrainers in photographic gelatins and their concentration is monitored closely for this appHcation (65). Elemental analysis of commercial gelatin is reported as carbon, 50.5% hydrogen, 6.8% nitrogen, 17% and oxygen 25.2% (66) a purer sample analy2ed for 18.2—18.4% nitrogen (18,20). Regulations for quaUty standards vary from country to country, but generally include specifications for ash content, SO2, heavy metals, chromium, lead, fluoride, arsenic, odor, and for the color or clarity of solutions (67). In addition, certain bacteriological standards, including E. coli and Salmonella are specified. Restrictions on certain additives and preservatives are also Hsted. In the United States, the Eood Chemicals Codex has been considering a new specification for food-grade gelatin a final version should be issued soon (ca 1995). Standard testing procedures for viscosity, pH, ash, moisture, heavy metals, arsenic, bacteria, and jelly strength are described (67,68,33). Additional test procedures have been pubflshed by the photographic and gelatin industries including the Japanese PAGI Method (69). Specific tests for photographic gelatin have been devised by the International Working Group for Photographic Gelatin (lAG) (70) in Fribourg, Swit2erland, and by individual photographic companies and gelatin companies.  [c.208]

Flotation Reagents. Only one sulfide mineral flotation collector is manufactured from phosphine, ie, the sodium salt of bis(2-methylpropyl)phosphinodithioic acid [13360-78-6]. It is available commercially from Cytec Industries Inc. as a 50% aqueous solution and is sold as AEROPHINE 3418A promoter. The compound is synthesized by reaction of 2-methyl-1-propene [115-11-7] with phosphine to form an iatermediate dialkylphosphine which is subsequently treated with elemental sulfur [7704-34-9] and sodium hydroxide [1310-73-2] to form the final product (14). The reactions described ia equations 10 and 11  [c.319]

Rhodium complexes with oxygen ligands, not nearly as numerous as those with amine and phosphine complexes, do, however, exist. A variety of compounds are known, iucluding [Rh(ox)3] [18307-26-1], [Rh(acac)3] [14284-92-5], the hexaaqua ion [Rh(OH2)3] [16920-31 -3], and Schiff base complexes. Soluble rhodium sulfate, Rh2(804 )3-a H2 0, exists iu a yellow form [15274-75-6], which probably coutaius [Rh(H20)3], and a red form [15274-78-9], which contains coordinated sulfate (125). The stmcture of the soluble nitrate [Rh(N03)3 2H20 [10139-58-9] is also complex (126). Another  [c.179]

Harvesting. In hand cutting practice, cane knives range from long machetes to shorter-handled Australian and Bra2ihan knives with hand guards. Cane leaves and tops (known as trash), which contain Httie sugar, add weight to transport, hinder cane cutters, and wear down mill roUs, are removed first by burning the cane field and then by hand or mechanical harvesters. Cane stalks are sufficientiy high ia moisture so that coatroUed and rapid bums (fire ia a 50-ha field is complete ia 3 min) iaciaerate only the leaves, tops, and trash. In Australia, Hawaii, and the Dominican RepubHc, cane is harvested without burning, to provide more fiber as fuel (for electricity cogeneration at the factory) and for environmental protection. A trash blanket is left on the field to encourage regrowth and discourage disease and pests. The harvesting of green cane is becoming more widespread, for environmental reasons, and as mechanical harvesting progresses. Important factors ia cuttiag are to produce clean, undamaged cane, free of trash, and to leave viable root stock ia the field. Mechanical harvestiag is fouad ia Australia, the United States, some Caribbean and Latin America countries, and new developing cane areas in Southeast Asia, and is gradually being introduced almost everywhere. Most common are combine harvesters, or chopper harvesters, developed in Australia, which cut cane stalks at the base, cut the stalk into billets, 28—38 cm long, blow excess leaves and trash off the billets, and drop the billets into a cane cart pulled alongside the combine harvester. In Louisiana, or where tonnage is light, soldier harvesters cut and top erect cane, leaving rows of whole stalks in the field, which are burned after harvest because the canopy is too light to support a bum on standing cane. Other whole-stalk harvesters in Hawaii, where cane tonnage is heaviest, are the V-cutter, which cuts cane at base but not at top, and the push-rake, used on hilly areas, which pushes cane, including the roots, out of the ground, necessitating replanting. Under good conditions, 0.5 t of cane per hour can be cut by hand and 30 t/h of cane by a combine harvester, with other mechanical systems between 15 and 30 t/h. Mechanical cuttiag is geaeraHy more expeasive than hand cuttiag and yields lower quality, more damaged cane, but is increasing for sociological reasons.  [c.16]

The European Union (EU) has a systematic classification of white sugars, shown in Table 10. Codex JUimentarius also has issued specifications for white sugars (17). The EU standards are widely used throughout Eastern Europe and Asia. Other countries, eg, Brazd and the People s RepubHc of China, have their own domestic specifications, which are also appHed to imports.  [c.20]

According to the Vood Chemicals Codex (96), the biologically active, food-grade form of biotin must have an assay of 97.5%, a melting point in the range of 229—232°C, and a specific rotation at 25°C in 0.1 NNaOH in the range of + 89—93°. It must also contain less than 3 ppm of arsenic and less than 10 ppm of heavy metals, eg, lead, mercury, and copper. Finally, it must be able to be quantitatively sieved through U.S. Standard Sieves No. 80 using a mechanical shaker. Biotin is Hsted as GRAS in the Code of Federal Regulations (97,98) for use as a nutrient or dietary supplement (21 CFR 182.5159). The specifications for i7-biotin for pharmaceutical appHcations are similar to those for food and are Hsted in the United States Pharmacopeia (99). No specifications for the optically inactive, dj-hioxin. are given for either food or pharmaceutical appHcations.  [c.33]

The AKD and ASA sizes are used in neutral to alkaline papermaking. ASA has the advantages of faster development of water-repellent properties and a lesser tendency to give sHp, but it is suppHed as a two-component system that must be emulsified shordy before use at the paper mill site, owing to the short active half-life of the ASA. Commercially available ASA sizes include Accosize (Cytec), Nalsize (Nalco), and Bersize (Bercen). AKD is suppHed as a one-part system as an aqueous emulsion. It has an active half-life measured in months at room temperature, but this can be extended with refrigerated storage. AKD-sized paper exhibits excellent resistance to penetration by acidic duids such as milk and fmit juice, as well as water. Commercially available AKD sizes include Hereon and Aquapel (Hercules Inc.), Rasiofob (Raisio), Keydime (Akzo Nobel), Basoplast (BASF), and Darasize (Grace Dearborn). In 1995, a new alkenyl reactive size, under the name Precis (Hercules Inc.), was introduced. It is best suited for fine paper grades where properties such as improved printabiHty are desired since it does not give the strong sizing of the AKD and ASA.  [c.310]

Benzaldehyde is sold as technical grade or as meeting the specifications of the NationalVormulary (NF) (7), the Vood Chemicals Codex (FCC) (8), or the British Pharmacopeia (BP) (9) (Tables 4 and 5). The test methods used for the analysis of benzaldehyde are standard methods, with the exception of the assay method.  [c.34]

Many microcarriers are now available commercially for mammalian cell culture. The choice of microcarrier depends to some extent on the cell line being used and whether a batch or continuous process is being contemplated. Table 4Hsts some of the microcarriers commercially available. The Cytodex family of beads is probably the most widely used. Cytodex 2 is recommended for cells having ftbroblasdike morphology Cytodex 3 is recommended for cells having an epithelial-like morphology. In long-term semm-free cultures, Cytodex 2 cells tend to retain cells longer than Cytodex 3, whereas the latter is usehil when available inoculum density is low. In some cases, productivity is affected by the surface characteristics. For example, some cells have higher productivity on negatively charged polystyrene, eg, Biosilon, than the positively charged dextran. In designing a microcarrier process, it is recommended that a quick screening experiment be conducted to assess the suitabiUty of the microcarriers available. A more extensive review of various types of commercial and noncommercial microcarriers and their appHcations is available (17).  [c.231]

Synchrotron radiation can be used to provide the same information, but also has the great advantj e of a wider, tunable, photon energy range. This allows one to access some core levels at higher resolution and surface sensitivity than can be done by XPS. The variable energy source also allows one to vary the surface sensitivity by varying the kinetic energy of the ejected photoelectrons, thereby creating a depth profiling capability. Most synchrotron photoemission work to date has involved fundamental studies of solid state physics and chemistry, rather than materials analysis, albeit on such technologically important materials as Si, GaAs, and CdTeHg. Some quite applied work has been done related to the processing of these materials, such as studying the effects of cleaning procedures on residual surface contaminants, and studying reactive ion-etching mechanisms. The major drawback of synchrotron radiation is that it is largely unavailable to the analytical community and is an unreliable photon source for those who do have access. As the number of synchrotron facilities increase and as they become more the domain of people wanting to use them as dedicated light sources, rather than in high-energy physics collision experiments, the situation for materials analysis will improve and the advantages over laboratory-based XPS will be more exploitable. Synchrotron radiation will never replace laboratory-based XPS, however, and it should be regarded as complementary, with advantj es to be exploited when really needed. High spatial resolution photoelectron microscopy is likely to become one such area.  [c.308]

In a dry 500-ml. three-necked flask, equipped with a reflux condenser, a mechanical stirrer, and a dropping funnel and protected from atmospheric moisture with drying tubes, are placed 6.0 g. (0.16 mole) of lithium aluminum hydride and 200 ml. of anhydrous ether. A solution of 43 g. (0.307 mole) of 3-ethoxy-2-cyclohexenone (Note 1) in 50 ml. of anhydrous ether is added, dropwise and with stirring, to the reaction flask at a rate which maintains gentle refluxing of the solvent (Note 2). After the addition is complete, the reaction solution is boiled under reflux for an additional 30 minutes and then allowed to cool. The complex is hydrolyzed and the excess lithium aluminum hydride is destroyed by the cautious addition, dropwise and with stirring, of 15 ml. of water (Note 3). The resulting reaction mixture is poured into 500 ml. of cold aqueous 10% sulfuric acid. The ether layer which forms is separated, and the residual aqueous phase is extracted with three 300-ml. portions of ether. The combined ether solutions are washed successively with one 100-ml. portion of water and one 100-ml. portion of saturated, aqueous sodium bicarbonate solution and then dried over magnesium sulfate. I lie ether is removed by distillation (lirougli a 5()-em. Vigreiix column,  [c.14]

Farr and Wright, who devised processes for the estimation of the total alkaloids as hydrochlorides, give the following percentages for the various parts of the plant stem, 0 01-0 06 leaves, 0-03-0-18 flowers, 0-09-0-24 green fruit, 0-73-0-98. The same authors quote 0-096-0-83 as the range of variation found in commercial samples of the fruit in 1904 and 1-05-3-6 as the range in fruits collected in England. The British Pharmaceutical Codex, 1934, quotes 0-2 per cent, for the leaves and 2-5 per cent, for the fruits. In British Columbia, where the plant has a larger habit than in England, Clark and Oflord found 0-025 per cent, in the stems and 0-92 per cent, in the fruits. An assay process for the fruits was given in the Eighth Revision of the United States Pharmacopoeia and 0-5 per cent, of total alkaloids was specified as a minimum.  [c.13]

Serves as a resource on all areas of emerging and existing air pollution prevention and control technologies, and provides public access to data and information on their use, effectiveness and cost. In addition, CATC provides technical support, including access to EPA s knowledge base, to government agencies and others, as resources allow, related to the technical and economic feasibility, operation and maintenance of these technologies.  [c.302]

FIGURE 20.1 I Universal calibration curve of PVP using CATSEC columns in an aqueous mobile phase of 0.20 N sodium nitrate/0.1 % trifluoroacetic acid.  [c.577]

In a 500-ml round-bottom flask fitted with a condenser, and a heating mantle is placed a mixture of 25 g of diethyl 5-(l -carboxy-2 -oxocyclohexyl)valerate, 70 g of barium hydroxide, and 200 ml of methanol, and the mixture is refluxed for 24 hours. After cooling, the mixture is acidified (pH 4) by cautious addition of cold 10% aqueous hydrochloric acid. The acidified solution is saturated with sodium chloride and then extracted three times with 100-ml portions of chloroform. The combined chloroform extracts are dried (anhydrous magnesium sulfate) and evaporated. On vacuum distillation, the residue affords the product (about 15 g), bp 176-17870.5 mm.  [c.100]


See pages that mention the term Cytotoxicity assays : [c.74]    [c.845]    [c.94]    [c.64]    [c.40]    [c.131]    [c.17]    [c.310]    [c.72]    [c.162]    [c.201]    [c.554]    [c.631]    [c.575]    [c.184]    [c.850]    [c.1122]    [c.68]    [c.165]   
Agricultural Chemicals and the Environment (1996) -- [ c.115 ]