Wash-water injection

The Skalar 12 DOC instrument allows variation of sample and wash water injection times and thus the volume of sample analysed and the period between the samples. This is the main reason why the instrument performs so well at low concentrations. Further, the instrument was never operated at concentrations above 20 mg L DOC to avoid contamination of the system. The main operating parameters are listed in Table A4.2, after optimisation of sampling and wash times. Chemicals were freshly prepared for each run, unless the instrument was used on consecutive days. Chemicals are not recirculated in the system. 

For salt related fouling, it was recommended to have 1 to 2% wash water injection upstream of the desalter. Some trial and error may be required to get the injection... 

A lower limit on wash water injection. This ensures the near-total removal... 

Monitor Ammonia Chloride in the Overhead Water, keep Ammonia Sulfide <5,000 ppm Use Steam Condensate as Water Wash at a Rate of 1-2 gpm/1000 bbl of Fresh Feed Use Ammonium Polysulfide Solution (especially if HCN > 25 ppm) to 10-20 ppm Residual HCN Make sure the Wash Water is injected uniformly into the Gas Stream Use Feed Forward Water Wash Scheme instead of Reverse Cascade ... 

These systems have been used in many bioanalytical applications. A Prospekt system coupled with MS quantitated eserine N-oxide, a cholinesterase inhibitor, in human plasma for low level (4.5 mg) oral administration pharmacokinetic studies (Pruvost et al. 2000). After conditioning of the SPE cartridge (PLRP-S, Spark) with methanol (5 mL/min, 0.5 min) and water (5 mL/min, 0.5 min), a volume of 250 jj.L plasma plus internal standard was injected and washed (water, 1 mL/min, 3 min). The analytes were flushed out with 80 20 ammonium acetate (20 mM, pH 3.5 adjusted with formic acid) and acetonitrile (0.3 mL/min) and separated on a Zobax SB-CN column (150 x 2.1 mm inner diameter, 5 jim). A calibration range of 25 pg/mL to 12.5 ng/mL was achieved with a run time of 10.5 min. 

Upon leaving the reactor, the effluent enters a drtim where ammonia injection neutralizes the catalyst, forming salts subsequent water injection dissolves the salts removing them from the system. The scale of this washing operation is small because the catalyst concentration is low-- with only about 15 gpm of process water required for 1000 BPSD of isohexenes product. If required, a subsequent small treating step can be supplied with the unit to remove anions from the wash water. 

Traditionally, it has been established that urine samples should be diluted 1 4 with water prior to an LC-MS analysis. Plumb et al. [92,93] reported obtaining good results from LC-MS analysis for rat urine after a 1 4 dilution with water. Waybright et al. [94] investigated the applicability of this dilution method to human urine which is less concentrated than mouse or rat urine. He concluded that a 1 4 dilution of human urine is not optimum for the detection of lower abundance metabolites. Although, the chromatogram for neat untreated urine was more intense, injection of neat urine on an HPLC column without column washing between injections was not recommended because of contamination of the HPLC column. 

If materials selection depends on corrosion control by process-related measures (such as chemical treatment), these should be indicated on the MSD. Indicate the intended injection points and the type of chemical to be injected. Examples include corrosion inhibitors, scale inhibitors, biocides, pH control chemicals, wash water, etc. Also indicate the location of proposed corrosion monitoring and sampling sites. If anodic or cathodic protection is to be part of the corrosion control design, the MSD or its Notes section should indicate the piping and/or equipment to be protected. 

Compound Solution of Alum. Rub together 1 ounce each alum and sulphate of zinc dissolve iu 3 pints boiling water. If necessary, filter. This is detergent and astringent, and is used as a lotion for old ulcers, excoriations < c. and, largely diluted with water, as an ere-wash and injection. 

Compound Alum Lotion. A detergent and astringent lotion for old ulcers, chilblains, excoriations, < c., and, largely diluted, as an eye-wash and injection. Dissolve 1 ounce each of alum and sulphate of zinc in 3 pints boiling water filter, if necessary. 

Sample preparation Plasma or serum. Condition a Sep-Pak C18 SPE cartridge with 2 mL MeOH then 2 mL water, do not allow to go dry. 500 pL Plasma or serum -I- 100 pL 100 pg/mL cephalexin in water -1- 50 pL 25% acetic acid, mix, add to SPE cartridge, wash with two 1 mL portions of water, elute with 3 mL MeOH. Evaporate eluate under nitrogen, add 200 pL mobile phase, vortex, inject a 25 pL ahquot. Urine. Dilute 100 1 (ratio may vary depending on concentration) with water, inject a 50 pL aliquot. 

M (NH4)2S04, combine the supernatants, inject an ahquot as described below. Plasma. Dilute with two volumes water, apply to 20 x 4 25-40 pm LiChroprep-NH2 equilibrated with 0.01 M (NH4)2S04, wash with 10 mL 0.1 M (NH4)2S04, elute with 1 mL 1 M (NH4)2S04, dilute the eluate with 10 volumes of water, inject an aliquot as described below. Apply up to 5 mL sample to column A with mobile phase A and elute for 10 min then backflush contents of column A onto column B vrith mobile phase B. Elute column B with mobile phase B and monitor the output. Re-equilibrate column A with mobile phase A. 

The prevention of such blisters is then proper water washing—preferably with steam condensate—of the wet gas after compression and withdrawing water that accumulates on the top trays of the stripper section. Polysulfide injection to the wash water is necessary for quantitative cyanide removal. 

The desalter should remove 90+% of the salts in crude. If it does not, check the desalter temperature (usually 270+°F). Steam condensate should be used for wash water. Is the proper dosage of desalter chemical being injected Is the voltage up to design ... 

Wheat bran and sodium hydroxide were blended at room temperature in a separate reactor one hour before each experiment. Tlie initial L/S ratio was seven and the mixture was stirred for five minutes. The L/S ratio was increased to ten just before the introduction of the mixture into the twin screw extruder with a Nemo excentric-screw pump. Straw was introduced in the extruder s first section with a screw feeder. Straw was mixed with the alkaline dough in the first zone of the barrel through the neutral pitch element and the reverse-pitch screw element successively. The washing water was injected downstream from this zone, and the mixture was conveyed through the second reverse pitch located just downstream from the filtration module. The filtrate was collected and kept in a cold room before further processing, while the refined cellulosic fibres were gathered at the barrel outlet. 

In the ultrafiltration of whey, protein concentrates depleted of lactose to various extents are obtained, depending on the number of stages and amount of wash water. Another, less gentle method involves the heating of whey (95 °C, 3 min) by direct steam injection, followed by precipitation of the denatured proteins at pH 4.5, separation in a sedimentation centrifuge (2000-4000 min ), and drying. 

HDS and HDN reactions produce H2S and NH3, respectively. Wash water is injected into the effluent from the last reactor to remove ammonia, which goes into the aqueous phase as ammonium bisulfide, NHiHSCaq). The NHjHSCaq) is rejected from the imit as sour water in downstream flash drums. 

Sample preparation Add 500 [iL plasma to a Varian SDB-XC SPE cartridge, wash with 1 mL MeOHiwater 15 85, elute with 750 p.L MeCN containing 0.1% trifluoroacetic acid. Evaporate the eluate to dr5uiess under a stream of nitrogen at 45°, reconstitute the residue with 100 gL MeCN, mix with 25 p.L water, inject an aliquot. 

Sample preparation Condition a 1 mL 30 mg Oasis HLB SPE cartridge with 1 ml. MeCNitrifluoroacetic acid 98 2 and 1 mT. water. Plasma. Mix 200 lL plasma with 100 xL of a solution of IS in water, make up to 1100 iL with water, add 1 mL to the SPE cartridge, wash with 500 aL water, wash with 500 (jiL MeOHrwater 30 70, elute with 1 mL MeCN trifluoroacetic acid 98 2, evaporate the eluate to dr5mess under a stream of nitrogen at 40°, reconstitute the residue with 100 aL MeOH water 50 50, centrifuge at 10 000 rpm at 4° for 10 min, inject a 30 iL aUquot. Urine. Mix 50 aL urine with 400 xL of a solution of IS in water, make up to 500 iaL with water, inject a 10 aL aliquot. 

Sample preparation Heat retina sample with 2 mg/mL proteinase K in buffer at 37° for 16—24 h, wash twice with phenohchloroform 50 50 (Caution Chloroform is a carcinogen ), wash with chloroform, evaporate to dr5mess under reduced pressure, suspend in water, inject an ahquot. Vitreous humor is similar, but buffer is not used. (Caution Chloroform is a carcinogen Buffer was 20 mM pH 8.0 Tris-HCl containing 0.5% Non-Idet P-40 (NP-40), 20 mM EDTA, and 100 mM NaCl.)... 

Sample preparation Condition a 1 mL 100 mg Bond Elut Cl SPE cartridge with 2 column vol of MeCN and 2 column vol of water. Mix 500 jiL serum with 25 aL 1 Xg/mL IS in MeCN, add 500 ih water, vortex for 5 s, add to the SPE cartridge, wash with 3 column vol of water, wash with 1 column vol of MeCN water 20 80, air dry at high vacuum for 10 min. Elute with 1 mL hexane chloroform 50 50 (Caution Cldoroform is a carcinogen ), evaporate the eluate to dr5mess under a stream of nitrogen at 45, reconstitute with 50 lL MeCN, vortex whUe adding 200 xL water, inject a 50 xL aUquot. 

Sample preparation Condition a 1 mL Bond Elut C2 SPE cartridge with two 1 mL portions of MeOH and three 1 mL portions of 2 mM phosphoric acid. Add 300 xL 500 mM phosphoric acid to the SPE cartridge, add 250 xL serum, add 50 p,L 500 ng/mL IS in mobile phase, add 250 p,L water, wash with 100 xL water, wash with 100 xL 100 mM phosphoric acid, elute with five 100 xL aliquots of MeOH 500 mM phosphoric acid 70 30, dilute the eluate with 500 p,L water, inject a 20 xL aliquot. 

Sample preparation Condition a 1 mL 100 mg Bond Elut CIS SPE cartridge with 2 mTi MeOH and 2 mL water. Vortex 500 iL plasma with 500 iL 5 rg/mL IS in MeCN for 1 min, centrifuge at 1500 g at 4°, add 800 iL of the supernatant to the SPE cartridge, wash with two 1 ml. portions of MeCNiwater 50 50, elute with two 1 mL portions of MeOH. Evaporate the eluate to dryness under a stream of nitrogen at 40, reconstitute the residue with 350 iL MeCN, vortex for 1 min, dilute with 150 aL water, inject an aliquot. 

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