Waters 2487 dual absorbance detector

Figure 19.2. A Waters 2695 high performance liquid chromatograph with a Waters 2487 dual absorbance detector operated by Waters Empower Software.

Accordingly GPC analysis of dried latex samples were carried out. The carrier solvent was tetrahydrofuran and peaks were monitored by a Waters dual absorbance detector at wavelengths of 2 h and 3U0 nm. The latter detection was the closest to 350 nm available. 

The analyses of aromatic components were performed on a 1525 Binary Waters HPLC with a dual absorbance detector using a Symmetry Cl 8 column and a mobile phase of methanol and water. Carboxylic acids analyses were performed using the same HPLC system with an Atlantis dC18 column and mobile phase. pH was monitored with a Coming 430 pH meter. For most experiments, the total organic carbon was also analyzed using a Shimadzu 5050 TOC analyzer equipped with a NDIR detector coupled with an autosampler ASI 5000. 

This work was done with a Waters Model 244 liquid chromatograph having two Du Pont Blmodal IIS columns (29,000 plates/meter) and a Linear dual-pen recorder. Also used was a Waters Model 440 UV absorbance detector. Samples were run at 0.1% (w/v) using an Injection volume of 25-pL and a flow rate of 1 mL/mln. The system was calibrated with polystyrene standards from Pressure Chemical Co. according to the universal callbaratlon procedure. Data collection and computation were done with an Intel 80/30 microprocessor. 

Liquid chromatographic separations were performed on a Waters Model ALC/GPC 204 liquid chromatograph equipped with two model 6000 pumps, a model 660 solvent programmer, and a model 440 dual UV absorbance detector. 

Pederson described a specific HPLC method for the determination of dipyridamole in serum [74]. The HPLC system used was a Waters model 600 liquid chromatograph equipped with a U6K injector, a pBondapak Ci8 column (30 cm x 39 mm) (10 pm), and a model 440 dual channel filter absorbance detector in conjunction with a Tarkan W + W 600 recorder. The mobile phase was a 75 25 mixture of methanol and a 0.02 M solution of sodium acetate (adjusted to pH 4 with acetic acid). The solvent flow rate of 2 mL/min was produced by an applied pressure of approximately 2000 p.s.i. Detection of the analyte was made at the UV absorption maximum of 280 nm. 

Fig. 7.2 HPLC separation of hyoscyamine 1 and scopolamine 6. The analysis was performed by using Waters HPLC system, equipped with Waters 1,525 binary pump, a Dual X Waters 2,487 absorbance detector, and Symmetry C18 reversed phase chromatographic column (250 mm x 4.6 mm, 5 pm). The operation temperature was 26 °C. The mobile phase consisted of acetonitrile methanol 0.05 mol ammonium acetate (20.9 27.9 51.2), and elution speed was 0.6 mL min in isocratic regime...

Capillary electrophoresis Capillary electrophoresis (CE) is used to analyze sodium, potassium, calcium, and magnesium in water samples. The detection is conducted by reverse absorbance measurements. Sufficient separation of the four cations is established with an electrolyte solution of 5 mM imidazole/6.5 mM a-hydroxyisobutyric acid/2 mM 18-crown-6 ether of pEI 4.1 [42]. CE with a contactless conductometric detector is used to determine small anions and cations in water samples from different sources. 2-(N-Morpholino)ethanesulfonic acid/histidine-based (Mes/Elis) electrolytes are used for direct conductivity detection of anions and cations, while ammonium acetate is used for indirect conductivity determination of alkylammonium salts. Eor the simultaneous separation procedure, involving dual-opposite end injection, an electrolyte consisting of 20 mM Mes/EIis, 1.5 mM 18-crown-6 and 20 mM cetyltri-methylammonium bromide provides baseline separation of 13 anions and cations in less than 6 min [43]. Also CE with a capacitively coupled... 

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