Filtration additive

Degobbis [60] studied the storage of seawater samples for ammonia determination. The effects of freezing, filtration, addition of preservatives, and type of container on the concentration of ammonium ions in samples stored for up to a few weeks were investigated. Both rapid and slow freezing were equally effective in stabilising ammonium ion concentration, and the addition of phenol as a preservative was effective in stabilising non-frozen samples for up to two weeks. 

Thus a biospecific adsorbant was obtained selective desorption should therefore permit successive elution of cellulolytic enzymes. It was thus found that the method was very useful in the purification of the cellobio-hydrolases from Tr. r., starting from very crude culture filtrates. Addition of glucose (0.1M) or gluconolactone suppressed the action of glucosidases present, preventing deterioration of the columns. The capacities exceeded 10 mg CBH I per ml gel (prepared with CNBr activated Sepharose). 

Homogenization of sample and extraction with acetonitrile, filtration, addition of salt and solvent evaporation. Redissolution of residue in acetone for analysis. 

The hot cyclohexane layer is carefully decanted, and the aluminum bromide layer is extracted with five 200-ml. portions of hot cyclohexane. Ether (400 ml.) is added to the cooled cyclohexane extracts (Note 11), and the combined solvent fractions are washed with two 100-ml. portions of water and dried over anhydrous magnesium sulfate. Evaporation of the solvent leaves a semi-solid residue that is partially dissolved in about 100 ml. of pentane. The undissolved white solid, diamantane, is collected by suction filtration. Additional diamantane is obtained by concentrating the pentane solution to a small volume and collecting the solid that precipitates. The total amount of diamantane obtained, after drying, is 60-62 g. (60-62%), m.p. 240-241° (closed tube) (Note 12). This product is sufficiently pure for most purposes, but it may be purified further by recrystallization from pentane to give white crystals, m.p. 244.0-245.4°. 

Fig. 3. Glucose production per liter of reactants over time for semibatch saccharification experiments at 15% (w/w) initial insoluble solids concentration and initial enzyme loading of 20 FPU/g of cellulose. Vacuum filtration was applied at two different times to remove glucose (vertical dashed lines). Fresh pretreated corn stover was added to replenish the volume removed by filtration. Additional enzyme was loaded at 5 FPU/g of fresh cellulose. The predicted curve was calculated by summing the amount of glucose generated by additional control experiments at 20 and 5 FPU/g of cellulose. Error bars represent averages 1 SD for two repeated experiments.

A mixture 31.3 g of o-chlorobenzoic acid, 32.2 g of trifluoromethyl-m-aminobenzene, 3 g of copper powder, 13.8 g of waterless potassium carbonate and 100 ml amyl alcohol was refluxed for 4 hours. To the cooled mixture was added 25 ml of 10 N solution NaOH and the mixture was concentrated and filtrated. Addition to the filtrate hydrochloric acid and water give a sediment of 2-((3-trifluromethyl)phenyl)aminobenzoic acid. After recrystallization from hexane 2-((3-trifluromethyl)phenyl)aminobenzoic acid have melting point 134-136°C. 

Field blanks—field blanks are performed by passing a volume of contaminant-free water through all processing equipment that an environmental sample would contact, including filtration, addition of preservative, transfer to the sample container in the field and shipping to the laboratory with field samples. The results of field blanks can be used to assess contamination issues associated with processing and transporting the sample. 

After filtration, addition of sodium sulphide to the clear solution effects the precipitation of the three metals, cobalt, nickel, and manganese, as sulphides. Digestion with the calculated quantity of ferric chloride oxidises the manganese sulphide to sulphate, which passes into solution. The residue consists of cobalt and nickel sulphides, which are washed and converted into their soluble sulphates by roasting. The sulphates are extracted with water, and converted into chlorides by addition of calcium chloride solution. Their separation is effected g.s follows The requisite fraction of the chloride solution is precipitated with milk of lime, and the insoluble hydroxides of nickel and cobalt thus obtained are oxidised to the black hydroxides by treatment with chlorine. The. washed precipitate is then introduced into the remainder of the chloride solution, and the whole is well stirred and heated, when the black hydrated oxide of nickel passes, into solution, displacing tlm Remainder of. the cobalt from the solution, into. the precipitate.. The final product is thus a suspension of hydrated peroxide.of cobalt,in p. solution of nickel chloride, from which idle cobalt precipitate is removed by filtration, washed, and ignited, to the black oxide. 

The focus of automation is not solely on HPLC anymore (since it is automated), but also includes the sample preparation procedure for drug products since it involves many labor intensive steps (weighing, addition of sample solvent, extraction procedure, mixing, filtration, additional dilutions, second mixing, etc.). So, if the sample preparation procedures are automated and combined with HPLC, then the entire analysis is said to be fully automated whether it is for assay, CU, blend analysis, or even for dissolution testing. Such automated workstations are currently available from number of vendors (Caliper Life Science, SOTAX Inc.), but their ability to integrate with HPLC or UV spectrophotometer is left to the end users. This open-ended option depends on the end user requirements. 

One and two-tenths grams (0.00275 mole) of (—)-cj5-bromoamminebis-(ethylenediamine)cobalt(III) dithionate from Sec. B is ground thoroughly with 4 ml of concentrated hydrochloric acid. The solution is allowed to stand in an ice bath for ca. 30 min, and the resulting deep red-violet crystals are collected by suction filtration. Additional product is obtained from the filtrate by addition of 12 ml of absolute ethanol. The combined crystals are dissolved in a minimum volume of water (ca. 4 ml), 2 ml of concentrated hydrochloric acid is added, and the solution is refrigerated overnight. The resulting crystals are collected by suction filtration, washed with absolute ethanol and ether, and then air-dried. The yield of (—)-chloride is 0.538 g (56.4%). For a 0.200% aqueous solution in a 2-dm tube, [aYc = —0.1886°, whence [or]p = —47.15° (Werner did not prepare the (—)-chloride, but he reported [aY = -t- 50.6° for the (+)-chloride the checkers report [a] = —50.6°). The checkers report =-155.2°. 

Over the past few decades, significant research efforts have focused on attaining a convergence of the two parallel development paths. Specifically, it is desired to create catalysts that possess the single-site nature of homogeneous catalysts but that are fixed to a substrate that is easily separated from the reaction mixture. This can be accomplished through catalyst immobilization onto solid, insoluble supports. These catalysts can then be used in flow reactor systems in a continuous fashion, or they can be used in batch reactors and recovered by filtration. Additionally for batch reactions, catalysts can be immobilized onto supports that are soluble under reaction conditions but that can be made insoluble at the end of the reaction (e.g., polymers that may be precipitated). 

A hot solution of 2 moles of hydroxylamine hydrochloride in 100 ml. of hot water is added to a hot solution prepared from 2 gram atoms of sodium and 1.61. of absolute ethanol and, after cooling, the sodium chloride formed is removed by suction filtration. Addition of 1 mole of cinnamic acid produces a voluminous precipitate of (2), which dissolves at the reflux temperature. After 5-6 hrs. the amino acid (3) begins to separate and in 9 hrs. the reaction is complete. The crystallized product is washed alternately with water to remove sodium chloride and with absolute alcohol for drying. 

A suspension of hydrazide 1 (10 g, 28 mmol) and N2H4 2 HC1 (13.1 g, 129 mmol) in HOAc (600 mL) was refluxed for 5 h to give a clear solution. Evaporation of the solvent in vacuo afforded crystals of the hydrochloride which were collected by suction and treated with a slight excess of 10% aq NaOH in HtOH/H20 to give a clear solution which was filtered and HOAc was added to acidify the filtrate. Addition of HjO followed by heating on a boiling water bath yielded the product as the monohydrate in the form of yellow needles yield 6.12 g (70%) mp 283-284 °C. 

During the degumming, the authors reported a sharp decline in the permeate flux at the beginning of the process of permeation and attributed this behavior to the concentration polarization and to membrane fouling, and this initial sharp drop in the flow was more intense in PES and PS membranes. The decline in the permeate flux was much less pronounced in the long term, 250 min, that initially, 50 min this trend implies that a system of consolidation of fouling caused by the cake may have affected the membrane after the initial filtration. Additionally, PVDF membranes achieved the highest retention of phospholipids, up to 98%. 

Silica sulfuric acid (SSA) has recently attracted the interest of many chemists (Ali et al., 2003 Azizian et al., 2005 Rapolu et al., 2013) thanks to its ability to enhance the reactivity and selectivity of many types of reactions such as oxidation (Miqalili et al., 2003), carbon-carbon bond formation (Chen and Lu, 2005), cycloaddition (Saheli et al., 2005), protection-deprotection steps (Hajipour et al., 2005), esterification (Chakraborti et al., 2009), and the synthesis of heterocyclic compounds (Maleki et al., 2012). SSA, which is prepared from the reaction of silica gel with chlorosul-fonic acid (Zolfigol, 2001), is easier to handle than sulfuric acid and can be readily separated from the products by simple filtration. Additionally, it is recyclable and may have applicability in the large-scale industrial synthesis of fine chanicals and pharmaceuticals. 

Crystals of NaOCl 2.5H2O can also be made. A 35-40% sodium hypochlorite solution is made by chlorinating sodium hydroxide. The precipitated salt is removed by filtration. Additional sodium hydroxide is added so that the solution contains at least 15% sodium hydroxide and 15% sodium hypochlorite. The solution is cooled to -O C when NaOCl 2.5H2O crystallizes. The crystals are removed by filtration, and the mother liquor is recycled into the process. Solid mixtures of sodium chloride and sodium hypochlorite are made by reacting a fine spray of sodium hydroxide with chlorine gas. The stability is improved by melting the solid and adding an anhydrous salt that forms a stable hydrate such as sodium metaborate, trisodium phosphate, " or sodium carbonate. " Solid sodium hypochlorite is also made by vacuum evaporation of concentrated sodium hypochlorite solution that is essentially free of chloride ions. ... 

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