Detectors sulfate

Tajima and co-workers [108] determined the surface excess of sodium dode-cyl sulfate by means of the radioactivity method, using tritiated surfactant of specific activity 9.16 Ci/mol. The area of solution exposed to the detector was 37.50 cm. In a particular experiment, it was found that with 1.0 x 10" Af surfactant the surface count rate was 17.0 x 10 counts per minute. Separate calibration showed that of this count was 14.5 X 10 came from underlying solution, the rest being surface excess. It was also determined that the counting efficiency for surface material was 1.1%. Calculate F for this solution. 

Deprotonation in Pu sulfate systems 260-61 Detector, IR fluorescence measurements of PuF6(g). 162... 

Thin-layer chromatography (TLC) is used both for characterization of alcohol sulfates and alcohol ether sulfates and for their analysis in mixtures. This technique, combined with the use of scanning densitometers, is a quantitative analytical method. TLC is preferred to HPLC in this case as anionic surfactants do not contain strong chromophores and the refractive index detector is of low sensitivity and not suitable for gradient elution. A recent development in HPLC detector technology, the evaporative light-scattering detector, will probably overcome these sensitivity problems. 

Sodium dodecyl sulfate present in hydrophilic ointments has been determined by TLC on silica gel with flame ionization detection, which was considered better than the colorimetric method. TLC is preferred to HPLC in this case due to the low sensitivity of the refractive index detector that makes difficult the analysis of small amounts of sodium dodecyl sulfate [284]. 

Alcohol sulfates and alcohol ether sulfates separated by HPLC on a styrene-divinylbenzene copolymer column with 4 1 (v/v) methanol and 0.05 M ammonium acetate aqueous solution as the mobile phase were analyzed by simultaneous inductively coupled argon plasma vacuum emission spectroscopy (IPC), monitoring the 180.7-nm sulfur line as a sulfur-specific detector [294]. This method was applied to the analysis of these surfactants in untreated wastewaters. 

HPLC coupled with an evaporative light scattering (ELS) detector has been used as an universal detection technique also valid for quantitative analysis. Alcohol ether sulfates were analyzed by this method with good results and also at very low concentrations [295]. 

Capillary tube isotachophoresis using a potential gradient detector is another technique that has been applied to the analysis of alcohol sulfates, such as sodium and lithium alcohol sulfates [303]. The leading electrolyte solution is a mixture of methyl cyanate and aqueous histidine buffer containing calcium chloride. The terminating electrolyte solution is an aqueous solution of sodium octanoate. 

GC/ECD or a halogen-specific detector (HSD) (Method 8080) is the technique recommended by EPA s Office of Solid Waste and Emergency Response for determining a- and [3-endosulfan and endosulfan sulfate in water and waste water at low-ppb levels (EPA 1986a). At these low concentrations, identification of endosulfan residues can be hampered by the presence of a variety of other pesticides. Consequently, sample clean-up on a Florisil column is usually required prior to analysis (EPA 1986a). 

High Performance Liquid Chromatographic (HPLC) Analysis. A Waters HPLC system (two Waters 501 pumps, automated gradient controller, 712 WISP, and 745 Data module) with a Shimadzu RF-535 fluorescence detector or a Waters 484 UV detector, and a 0.5 pm filter and a Rainin 30 x 4.6 mm Spheri-5 RP-18 guard column followed by a Waters 30 x 3.9 cm (10 pm particle size) p-Bondapak C18 column was used. The mobile phase consisted of a 45% aqueous solution (composed of 0.25% triethylamine, 0.9% phosphoric acid, and 0.01% sodium octyl sulfate) and 55% methanol for prazosin analysis or 40% aqueous solution and 60% methanol for naltrexone. The flow rate was 1.0 mL/min. Prazosin was measured by a fluorescence detector at 384 nm after excitation at 340 nm (8) and in vitro release samples of naltrexone were analyzed by UV detection at 254 nm. 

Lin [1] used coprecipitation with lead sulfate to separate 237actinium from seawater. The 237actinium was purified by extraction with HDEHP and determined by G -spcclromclry with a Si (Au) surface barrier detector. The method has a sensitivity of 10 3 Ci/g of ashed sample. 

GC = gas chromatography HC1 = hydrochloric acid HPLC = high-performance liquid chromatography MS = mass spectrometry Na2S04 = sodium sulfate NR = not reported UV = ultraviolet detector... 

Analytical Procedures. Incubation mixtures were extracted with diethyl ether except in the case of toxaphene where a mixture of chloroform-methanol (5 1, v/v) was used instead. Ether extracts of DDT, dieldrin, and lindane were dried over anhydrous sodium sulfate, evaporated using a gentle stream of nitrogen, and the residues were redissolved in n-hexane. Aliquots of the hexane solutions were directly injected into a gas liquid chromatograph (GLC, Varian, model 240 ) equipped with an electron capture (EC) detector (Aerograph Sc H detector) and a 1.5% 0V-101 on chrom GHP 100/120, 5 x 1/8" stainless steel column. The detector temperature was 245°C, injection port 235°C, and the oven temperature was 125°C for lindane, 180°C for DDT and 200°C for dieldrin. Carrier gas was nitrogen at the flow rate of 40 ml/min. 

For a fluorescence detector, quinine sulfate is used as the standard compound. The flow cell is filled with a standard solution and the fluorescence intensity is measured. The value is compared with that measured by a fluorescence spectrophotometer. This standard solution is also used for fixing the wavelength and position of the flow cell. The Raman spectrum of water can also be used for this purpose. 

Figure 4.22 High temperature size-exclusion liquid chromatography of an engineering plastic, poly (phenyl sulfate). Column, SSC GPS-3506, 50 cm x 8 mm i.d. eluent, 1-chloronaphthalene flow rate, 1.0 ml min-1 column temperature, 210 °C detector, refractive index detector.

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