Dichloromethane, DCM

Health risks during furniture stripping using dichloromethane (DCM)... 

Partition the sample in methanol twice with 2mL of dichloromethane (DCM), remove the DCM after each partition step and pass the sample in DCM through a 6-mL filtration tube containing a polyethylene frit and packed with 1 g of anhydrous sodium sulfate. The use of the anhydrous sodium sulfate can be eliminated if great care is taken when removing the DCM from each partition step so that no water is included with the DCM. If water droplets are present in the DCM fraction, carefully remove them with a small pipet. The DCM is then concentrated in a Turbovap to 0.1 mL at 50 °C. Note there is the potential for loss of analytes if the samples go to dryness at this step. 

Water samples are directly partitioned with dichloromethane (DCM). The DCM exAact is then rotary evaporated and driven to dryness with a sAeam of niAogen. The dry residue is dissolved in acetone and analyzed by gas chromatography/nitrogen-phosphorus detection (GC-NPD). 

Sodium sulfate, anhydrous, ACS grade (Fisher Scientific) or equivalent Solvents acetonitrile (ACN), acetone, dichloromethane (DCM), methanol (MeOH) and water (pesticide or HPLC grade)... 

The crude organic solvent preparations were produced by sequential extractions of the plant material with petroleum ether (PE), followed by dichloromethane (DCM), and finally methanol (MeOH). 

Solution SHS-GC-FID was used for the determination of dichloromethane (DCM) in PC [222] and solid SHS-GD for the analysis of residual solvents in transdermal drug-delivery systems [223] and rest... 

Reduction of 2,2-bisf3 -nltro-4 -(4"-phenylsulfonylphenoxyl)phenyl1 propane. Compound 9, 200 mg (0.55 meg) was dissolved in a mixture of 30 mL of dichloromethane (DCM) and 30 mL of methanol and 240 mg of 10% palladium on charcoal was added. After purging the solution with argon for 30 min, 520 mg (13.6 mmol) of sodium borohydride was added portionwise over 10 min. The reaction mixture was stirred under argon for 1 hr before addition of 30 mL of DCM. The mixture was filtered, the filtrate evaporated, and the residue extracted with DCM. Evaporation of the extract yielded 140 mg (76.2%) of 2,2-... 

When dichloromethane (DCM) solutions of the polyenes which had been prepared as described (39) were added to DCM solutions of TFA new species were formed which had strong absorptions in the region 500-850 nm. Figure 6 shows seme typical spectra for such a solution, (a) immediately after mixing, (b) after a further 20 minutes and (c) after 200 minutes. In spectrum (a) clearly defined maxima are visible at 590, 660, 730 and 790 nm the intensities of which change with time in a way which indicates that they are inter-related (figure 7). As Arg0 decreases,... 

Extraction is usually performed in a solvent such as dichloromethane (DCM), chloroform, methanol, or a mixture of them, to obtain the so-called total lipid extracts (TLEs). 

For the evaluation of the response of the sensor, we selected several vapors of different polarity. The vapors included water (H20), acetonitrile (ACN), toluene, and dichloromethane (DCM). Solvent polarity and refractive index of tested vapors are listed in Table 4.346 47. The spectral range for the evaluation of the vapor responses of the colloidal crystal film was selected as 700 995 nm, which covered only the fundamental Bragg diffraction peak on the (111) planes of the colloidal crystal film to further reduce effects from possible stacking defects in the film as suggested in the literature44. 

A range of other terminal alkenes has been hydrogenated with ruthenium-diphosphine catalysts. The first set of substrates (Fig. 30.7 Table 30.5) was hydrogenated with Ru-BINAP in dichloromethane (DCM) at 30°C. Products of double bond migration were also detected [5]. 

The following quaternary ammonium salts are used as phase transfer catalyst tetra-K-butylammonium chloride (TBAC), tetra-n-butylammonium bromide (TBAB), benzyltriethylammonium chloride (BTEAC), and benzyltriethylammo-nium bromide (BTEAB). Chlorinated hydrocarbons, such as dichloromethane (DCM), chloroform (CF), tetrachloromethane (TCM), 1,2-dichloromethane (DCE), and nitrobenzene (NB) are used as solvents. The effects of phase-transfer catalyst and solvent on the yield and reduced viscosity are summarized in Table 9.1. 

A total of 10.0 g (8.9 mmol) SASRIN resin2 (note 1) was washed with N,N-dimethyIfonnamide (DMF 2 x 25 mL), methanol (MeOH 2 x 25 mL), and dichloromethane (DCM note 2 2 x 25 mL), and dried under vacuum (0.5 torr) at 70°C overnight. To a suspension of the dried SASRIN resin in lOOmL of methyl sulfoxide (DMSO note 2) and 25 mL of DCM was added 12.4 mL (89 mmol, 10.0 Eq.) triethylamine (note 2) followed by 7.1 g (44.5 mmol, 5.0 Eq.) sulfur trioxide-pyridine complex (note 2). The suspension was shaken on a radial arm at room temperature overnight (note 3) filtered on a glass frit and washed with DCM (3 x 100mL), DMSO (3 x lOOmL), DCM (3 x lOOmL), and tetrahydrofuran (THF 3 x 100 mL) and dried under vacuum (0.5 torr) at room temperature to give 10.0 g Ameba resin (notes 4 and 5). 

In the course of our polarographic studies on organic cations we determined the half-wave potentials, 1/2, for various arylmethylium ions [1-11]. The aim of the present work is to extract from these values some new information concerning the relative magnitude of their solvation enthalpies in three very different solvents. A comparison of our results [obtained in methanesulphonic acid (MSA) and dichloromethane (DCM)] with those of Volz and Lotsch [12] [obtained in cyanomethane (CM) solutions] yields some useful conclusions. 

The advantages of using ionic liquids as solvents for Diels-Alder reactions are exemplified by the scandium triflate catalysed reactions [14] in [bmim][PFg], [bmim][SbF6] and [bmim][OTf] for the reaction shown in Scheme 7.6. Whilst the nature of the anion seems to have little effect, all these solvents give rate enhancements for a range of Diels-Alder reactions compared to when the reactions are carried out in dichloromethane (DCM). Also, the selectivity towards the endo product is higher than in conventional solvents. As well as the enhanced rates and selectivities, the products can also be removed by extraction with diethyl ether and the ionic liquid and catalyst can immediately be reused. Experiments... 

AT-Acyl-L-HSL can be conveniently prepared in excellent yields by the acylation of l-HSL either with the corresponding carboxylic acids activated with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) in a water/ 1,4-dioxane (1 1) solvent system or with the corresponding acid chlorides in dichloromethane (DCM) in the presence of triethylamine (Scheme 4) [15,16, 37,53]. 

The structure of A -sulfinyl compound 39 was solved using a single crystal grown by the slow evaporation of a solution of dichloromethane (DCM) and hexane (Figure 7) <2003T4651>. The A -sulfinyl compound crystallizes with two molecules in a unit cell. This work provides additional evidence for the (Z)-preference of this dienophile used in [4-1-2] cycloaddition reactions to prepare 1,2-thiazines. 

The samples were analyzed for trace metals and sulfate as well as for three fractions of particulate organic matter (POM) using sequential extraction with cyclohexane (CYC), dichloromethane (DCM) and acetone (ACE). Factor analysis was used to identify the principal types of emission sources and select source tracers. Using the selected source tracers, models were developed of the form POM = a(V) + b(Pb) + - - -, where a and b are regression coefficients determined from ambient data adjusted to constant dispersion conditions. The models for CYC and ACE together, which constitute 90% of the POM, indicate that 40% (3.0 pg/m ) of the mass was associated with oil-burning, 19% (1.4 pg/m ) was from automotive and related sources and 15% (1.1 pg/m ) was associated with soil-like particles. 

Solid-phase syntheses have become increasingly popular during the period of this review, with examples including the synthesis of 5,6,7,8-tetrahydro[l,6]naphthyridines from Meldrum s acids derived from /3-amino alcohols via Hantzsch condensation and cyclization with cyclative cleavage from the resin (using 70% trifluoroacetic acid (TFA)/dichloromethane (DCM) followed by 5% triethylamine/DCM) <1999S1951> and also of isoquinolinones and 5-oxo-5,6-dihydro-[l,6]naphthyridines <1995JOC5748>. 

Itou et al. [60] determined 0II/0C for isotropic solutions of poly(n-hexyl isocyanate) (PHIC) and dichloromethane (DCM) from sedimentation equilibrium data on narrow distribution PHIC samples. Figure 3 shows their results, where the ordinate Mw(0II/0c) represents the osmotic pressure increment on the molar concentration scale. 

Fig. 7. Comparison of experimental phase boundary concentrations between the isotropic and biphasic regions for various liquid-crystalline polymer solutions with the scaled particle theory for wormlike hard spherocylinders. ( ) schizophyllan water [65] (A) poly y-benzyl L-glutamate) (PBLG)-dimethylformamide (DMF) [66-69] (A) PBLG-m-cresoI [70] ( ) PBLG-dioxane [71] (O) PBLG-methylene chloride [71] (o) po y(n-hexyl isocyanate) (PHICH°Iuene at 10,25,30,40 °C [64] (O) PHIC-dichloromethane (DCM) at 20 °C [64] (5) a po y(yne)-platinum polymer (PYPt)-tuchIoroethane (TCE) [33] ( ) (hydroxypropyl)-cellulose (HPC)-water [34] ( ) HPC-dimethylacetamide (DMAc) [34] (N) (acetoxypropyl) cellulose (APC)-dibutylphthalate (DBP) [35] ( ) cellulose triacetate (CTA)-trifluoroacetic acid [72]...

Analysis for NMOR Ten mL of thawed urine were placed on a Preptube cartridge (Thermo Electron Corp.) and eluted with 60 mL of dichloromethane (DCM). The Preptube was pre-wet with DCM before receiving the sample. The resulting solution was concentrated to a volume of 1 mL at 55°C using a Kuderna-Danish apparatus. The concentrate was analyzed for NMOR by GC-TEA. Recoveries of the internal standard (NPiP) were typically 80-100%. 

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