Perkin Elmer Lambda 6 spectrophotometer

The ultraviolet—visible (UV—Vis) spectra were obtained on a Perkin-Elmer lambda 6 spectrophotometer with a tungsten lamp for excitation in the visible wavelength range and a deuterium lamp for excitation in the ultraviolet wavelength range. 

Ultrasonic treatment was performed using a high-intensity ultrasonic probe (Sonic and Materials VC-600, 1/2" titanium horn, 20 kHz, 100 W/cm ). Films were cast using a Specialty Coatings Systems P-6204-A spin-coater. Film thickness was measured using a Tencor Alpha-Step 200 profilometer. UV/visible spectra were measured on a Perkin-Elmer Lambda 6 spectrophotometer from 190 to 900 nm using a 1-nm slit at a scan rate of 120 nm/min. 

Pectolytic activity was also studied in batch reactors, following the reaction progress in thermostated quartz cuvettes. The reaction medium (3 cm ) was prepared with 1.5 g/L pectin in the standard buffer and 0.063 mg of enzyme. The absorbance of the reaction mixture against the substrate blank was continuously recorded at the spectrophotometer (Perkin Elmer Lambda 2, USA). Typical reaction time was 15 minutes, but initial reaction rates were estimated considering only the absorbances recorded during the first 200 seconds, range of totally linear response. 

APPARATUS AND MATERIALS. A Mettler DL40 memotitrator, DK19 Filter Titrator with filters and a DK181 Phototrode were purchased from M.S.E. Scientific Instruments, Crawley. Visible spectra were recorded on a Perkin Elmer Lambda 3 spectrophotometer. 

Samples were characterized by FTIR spectroscopy with a Perkin Elmer (Spectrum BX) spectrometer using KBr pressed disks as matrices. The DRIFT experiments were carried out with a Broker IFS 55 spectrometer equipped with a Thermo Spectra Tech reacting cell. UV-vis Diffuse Reflectance spectra were recorded on a Perkin Elmer Lambda 45 spectrophotometer equipped with a diffuse reflectance attachment. Raman spectra were collected with Perkin Elmer system 2000 NIR FT-Raman using as excitation radiation the 5th harmonic of a diode pumped Nd YAG laser (1065 nm). 

DOX concentration was determined spectrophotometrically based on the molar extinction coefficient of 125000 OD M (38) in a dual-beam spectrophotometer (either Perkin-Elmer Lambda 3B or Kontron Uvikon 860). The DOX quantification was confirmed by HPLC (49-51). Purity of DOX and its degree of degradation during the processes of liposome preparation and liposome storage were determined by a combination of HPLC and TLC, as described by Barenholz leave et al. (38,49,50). 

Instrumentation. UV/Visible spectra were collected on a Perkin-Elmer Lambda 4 spectrophotometer. IR spectra were collected on a Perkin-Elmer 1640 spectrophotometer. NMR spectra were taken on a Nicolet NT-200 spectrometer. Differential scanning calorimetry was run on a Perkin-Elmer DSC-4 unit, equipped with a system 4 microprocessor controller and a 3600 data station. Elemental analyses were run by the Purdue microanalysis laboratory in the Department of Chemistry at Purdue University and by Huffman Labs (Golden, CO). Lignin group analysis techniques are described in references 19-21. 

The X-ray diffraction (XRD) patterns of the sample were measured using Rigaku D-Max. II VC X-ray diffractometer using nickel filtered Cu Ka (X= 1.5406 A) radiation. The specific BET surface area and average pore sizes were determined by N2 adsorption-desorption isotherms at 77 K using an Omnisorp-lOO. Diffuse reflectance UV-spectra were obtained using Perkin Elmer Lambda 5 spectrophotometer using mesoporous silica MCM-41 or MCM-48 as a standard. The details are already reported earlier [27]. 

Optical Absorption. Figure 3 compares the optical absorption spectra of undoped, Co-, Mn-, and Fe-doped BaTi03 crystals grown in air. Transmission spectra were obtained on a Perkin-Elmer Lambda 9 spectrophotometer modified for use with polarized light and were reduced to absorption coefficients by correction for Fresnel... 

Spectroscopy. UV-VIS reflectance spectra of the pulps were recorded directly after irradiation in the wavelength range 250-750 nm on a Perkin-Elmer Lambda 15 spectrophotometer equipped with an integrating sphere. The reflectance values (RM, strictly speaking the reflectivity of an infinitely thick specimen) at 457 and 557 nm were taken from the reflectance curves. Difference spectra were calculated by subtracting the spectrum of the irradiated pulp from the spectrum of the unirradiated one. 

Solution-phase ultraviolet absorption spectra of racemic mandelic acid were obtained using a Perkin-Elmer Lambda 3B spectrophotometer. Spectra (referenced against the corresponding solvent) of the protonated form were obtained in ethanol (Figure 8), and of the deprotonated form in 0.5N NaOH (Figure 9), both at concentrations of 0.1 and 0.01 mg/mL. 

Absorption spectra were recorded with a Perkin-Elmer Lambda 5 spectrophotometer in 1 cm quartz cells. The emission spectra were recorded with an MPF-3 Hitachi spectrofluorimeter, also in 1 cm quartz cells. 

Instrumentation. Absorption spectra for the pyrenyl dye were obtained by using a Perkin-Elmer Lambda 2 UVA is/NIR spectrophotometer. The spectrophotometer is interface to a 286 computer to store spectra and control the instrument. Each spectrum was recorded using a PECSS program (Perkin-Elmer). Fluorescence spectra were recorded on an SLM 8000 spectrofluorometer interfaced to an IBM PS/2 computer. 

The BET surface area and pore volume and diameter of the catalysts were obtained by nitrogen adsorption at -196°C after heat pretreatment under vacuum for 4h at 350°C. The XRD patterns were collected with a Bruker D5005 diffractometer (50 kV, 35 mA) between 3 and 80° 20 using CuKa radiation. The UV-Vis DR spectra were recorded at ambient conditions with a Perkin-Elmer Lambda 19 spectrophotometer equipped with an integrating sphere reflectance accessory. The measurements were carried out at wavelengths ranging from 200 to 2000 nm, using MgO as a standard white reference. 

Diffuse Reflectance UV-Vis DR UV-Vis spectra of differently loaded V20s/Si02 samples, calcined in situ in O2 at 600°C, were obtained by a Perkin Elmer Lambda 19 spectrophotometer, equipped with an integrating sphere. 

Characterization of catalysts The zeolite structure was checked by X-ray diffraction patterns recorded on a CGR Theta 60 instrument using Cu Ka, filtered radiation. The chemical composition of the catalysts was determined by atomic absorption analysis after dissolution of the sample (SCA-CNRS, Solaize, France). Micropore volumes were measured by N2 adsorption at 77 K using a Micromeritics ASAP 2000 apparatus and by adsorption of cyclohexane (at P/Po=0.15) using a microbalance apparatus SET ARAM SF 85. Incorporation of tetrahedral cobalt (II) in the framework of Co-Al-BEA and Co-B-BEA was confirmed by electronic spectroscopy [18] using a Perkin Elmer Lambda 14 UV-visible diffuse reflectance spectrophotometer. Acidity measurements were performed by Fourier transform infrared spectroscopy (FT-IR, Nicolet FTIR 320) after pyridine adsorption. Self-supported wafer of pure zeolite (20 mg/cm ) was outgassed at 673 K for 6 hours at a pressure of lO Pa. After cooling at 423 K, the zeolite was saturated with pyridine vapour (30 kPa) for 5 min, evacuated at this temperature for 30 min and the IR spectrum was recorded. 

The HPLC was a Du Pont 8800 quaternary solvent system with a Hewlett-Packard (HP) 1040A photodiode array detector (5-8). Flexible disks were used for data storage, and postrun data evaluation was performed by the detector s computer (HP 85). Samples were injected with a loop injector 10 p,L was used for analytical scale, and 200 jlL was used for preparative scale. Spectra were run on a spectrophotometer (Perkin-Elmer Lambda 3) for static absorbance and on a spectrofluo-rometer (Perkin-Elmer MPF-66) for fluorescence. Field-ionization mass spectra were obtained at a resolution of 45,000 (corresponding to a 0.01-daltons error for a mass of 450). 

The samples have been prepared by e-beam evaporation of a dielectric layer followed by thermal evaporation of the silver fraction, which builds the island film, while the sandwich is completed by a further dielectric film. In every sample, intentionally the same amount of silver (corresponding to an average thickness of 4 nm, as recorded by quartz monitoring) has been embedded in a 6 nm thick dielectric film, formed from either Mgp2, LaFs, Si02, or AI2O3. The optical transmittance T and reflectance R of all films have been measured by a Perkin Elmer Lambda 19 spectrophotometer. To correlate the optical properties with the sample morphology, transmission electron microscopy (TEM) has been applied. 

Diffuse reflectance spectra were obtained with a Perkin-Elmer Lambda 9 spectrophotometer using BaS04 as a reference. The Kubelka-Munk function was used to express the esgserimental data. 

For UV diffuse reflectance measurements CVD powder was placed in a high vacuum tight quartz cell with optical windows made of Suprasil. Thermal activation, as well as adsorption and desorption steps were performed by connecting the cell to a conventional vacuum line that also guarantees pressures less than 10" mbar. The UV spectra were acquired using a Perkin Elmer Lambda 15 spectrophotometer equipped with an integrating sphere. BaS04 powder was used as a reference. 

A Perkin Elmer Lambda 3 uv-vlsible spectrophotometer was used In the peroxide assays. The algae suspensions were filtered using... 

The spectra were not corrected for the spectral variation in the excitation source and photomultiplier tube sensitivity. Background scattered light was zeroed electronically before the acquisition of the fluorescence of 4-methylcoumaro-[222]cryptand. Absorption spectra were obtained using Perkin Elmer Lambda 7 UV/VIS Spectrophotometer. 

IR-spectra were taken on a Bomem FT-spectrometer model M 100 under an argon atmosphere. UV-VIS-NIR-spectra were recorded on a Perkin-Elmer Lambda 9 UV-VIS-NIR-spectrophotometer under argon atmosphere. Gel permeation chromatographic ( GPC ) analyses were carried out at 25 °C employing a Perkin-Elmer Series 10 Liquid... 

The molecular weight and the molecular weight distribution were calculated based on monodispersed polystyrene standards. The FTIR spectra were recorded on a Nicolet 20 SXB FTIR spectrometer. A Perkin-Elmer Lambda 6 UVA is spectrophotometer was used to record the UVATS spectra. Thermal analyses were perform using die DSC-10 and TGA-50 systems from TA Instruments. Elemental analyses were performed by Adantic Microlab, Inc. A Metricon Model 2010 prism coupler was used to measure the refractive indices of the polyimides. A He-Ne laser (632.8 hm) and two diode lasers (780 nm and 1300 nm) were used as die light sources. 

For the optical characterization, the samples were cut directly from the extruded material. Absorption spectra were recorded on a Perkin-Elmer Lambda 9 spectrophotometer and on an Ocean Optics fiber optic spectrometer. The reflectance spectra were recorded using the fiber optics spectrometer with a reflectance probe. 

RCs were purified using a DEAE chromatography method developed for Rb. capsulatus (10). Bacteria were grown under microaerophilic conditions (nonphotosynthetic) to avoid selection of undesirable revertants. Optical spectra were recorded with a Perkin-Elmer Lambda diode array model 3840 spectrophotometer interfaced to a model 7300 workstation. RC pigment content was determined (6) through the absorbance of near-infrared pigment bands after extraction of RCs with acetone/methanol, 7 2 (voLvol). 

Figure 18. Solubility of AQ08 in carbon dioxide as a function of density, according to Tuma [47,76] (the isotherm measured up to concentrations of ca. 70 10 mol dm only (310.1 K) was determined with a Cary 17H spectrophotometer, that at 303.2 K in another optical high-pressure cell [74], all others with a Perkin-Elmer Lambda 18, respectively the data for 310.1 K (indicated by o) were obtained according to the dynamic method [40]).

UV/visible spectra and kinetic data were collected on a Perkin-Elmer 559A spectrophotometer or a Perkin Elmer Lambda 40 spectrophotometer. Product yields were determined on a Perkin-Elmer LC-235 HPLC equipped with a 235C diode-array detector measuring absorbance at A. = 220 nm and a LC 240 fluorescence detector, (ex. X = 210 nm, em X = 330 nm). The HPLC was fitted with a Rainin Microsorb-MV C-18 reverse phase column (4.6 mm ID x 25 cm 5-nm particle size) a 200 pi sample loop. The mobile phase for product separation was 80% MeOH/20% H2O with a flow rate of 0.8 ml/min for ail runs. Reported peak areas are averages of triphcate injections. Solution pH was measured with an Orion combination pH microelectrode, model 8103. a spin-lattice relaxation times, Ti, were measured on a Varian VXR-200 and... 

---