Perkin-Elmer computer

Through the use of an RS 232C interface, both instruments may be connected to Perkin-Elmer computers for instrument control and external data manipulation. 

Perkin-Elmer Computer-Aided Chemistry Seminar and Exhibition, January 8 and 9, 1981,and personal communication with G. Williams, Perkin-Elmer Sales Engineer Hyman, M Rowe, M.W Determination of the Calorific Value of Coal by Thermogravi-metric Proximate Analysis, J Chem Edn, submitted 1981. 

The sensitivity of the fluorescence methods varies considerably with the instrument used. Advances in modern instrumentation and the power of today s computers allow for a much improved sensitivity. Using commercially available instruments and modern computers equipped with appropriate software, detection limits down to 10 pg of calf thymus DNA can be achieved using ethidium bromide. (We have achieved such levels using several Perkin-Elmer MPF66 Instruments at various locations.)... 

All samples were monitored using a Perkin-Elmer 650-10S Fluorescence Spectrophotometer. Fluorescence excitation and emission wavelengths for the PAHs in this study were obtained from Berlman (24). The resulting spectra were analyzed using an Apple 11+ computer by integrating peak areas to determine total changes in... 

A laboratory spectrosieter, Perkin-Elmer MPF-44B, is being used to acquire RTF data. Cyborg Corporation s Integrated System for Automatic Acquisition and Control and an Apple 11+ computer have been... 

Fluorescence spectrometers are equivalent in their performance to singlebeam UV-visible spectrometers in that the spectra they produce are affected by solvent background and the optical characteristics of the instrument. These effects can be overcome by using software built into the Perkin-Elmer LS-5B instrument or by using application software for use with the Perkin-Elmer models 3700 and 7700 computers. 

Methods. Absorption spectra were recorded using an Hitachi model 150-20 spectrophotometer/data processor system. Uncorrected steady-state fluorescence emission spectra were recorded using a Perkin-Elmer MPF-44A spectrofluorimeter. These spectra were collected and stored using a dedicated microcomputer and then transferred to a VAX 11/780 computer for analysis. Fluorescence spectra were corrected subsequently for the response characteristics of the detector (21). Values of the fluorescence quantum yield, <) , were determined relative to either quinine bisulfate in IN H2S04 )>f =... 

Fluorometers designed for research purposes(31) are typically equipped with a xenon arc lamp, monochromators, one or more photomultiplier tubes, cuvet holders, and a computer interface. Some research level fluorometers, such as the Perkin-Elmer LS50, have optional microtiter plate reading accessories with fiber optic bundles. This is convenient since 96-well microtiter plates are commonly used for immunoassay development, and many commercial immunoassays are based on the use of microtiter plates. Fluorometers designed for commercial immunoassay purposes are generally dedicated instruments with few, if any, data acquisition and reduction parameters that can be manipulated by the user. 

High resolution proton magnetic resonance (PMR) spectra were recorded on a Perkin-Elmer R-10, 60-megacycle per second spectrometer fitted with a decoupling unit, a temperature probe, and a computer averaging attachment. Unless specified otherwise, spectra were obtained at 33.5°C. Chemical shifts in the high resolution NMR spectra are expressed as usual in parts per million relative to the protons of tetra-methylsilane at 10 p.p.m. (t scale). 

MINICOMPUTERS. The next step up is a minicomputer based integrator, which may service up to perhaps two to three dozen chromatographs simultaneously. Examples of this class are the 3352-B system of Hewlett-Packard and the PEP-2 system of Perkin-Elmer. The minicomputer may have multiple input/output devices to service two or more locations independently, and may make the computer available (through a language like BASIC) to do further calculations on chromatographic results or to do general laboratory calculations. 

Sodium Measurements. The sodium ion content was measured by two techniques 1) A Perkin-Elmer 403 atomic absorption unit was used to obtain the total amount of sodium in a particular solution and 2) an Orion 801 pH meter with Corning sodium-specific ion electrodes was used at 25 °C to determine the free sodium present. An attempt to measure the free sodium content at 60 °C failed because of thermal instability. It was especially important to determine if the sodium ions present were free so that correct molecular weights could be computed from the VPO data. The calibration was accomplished by dissolving small amounts of sodium benzoate in the DMF, or by using DMF-distilled water (3 + 1) mixtures containing dissolved NaOH. Both calibrations gave similar final results. Even though tap water was used in the synthesis, interference from other ions (e.g., Ag+, Li+, or NH4+) was considered minimal be-... 

All XPS or ESCA measurements were performed using a Perkin Elmer 5300 ESCA spectrometer equipped with a dual anode (Mg, Al) X-ray source, differentially pumped Ar+ sputter gun, and the variable angle measurement set-up for angle-resolved photoelectron spectroscopic measurements. The data collection and treatment, e.g. smoothing, curve-fitting, intensity measurements, were accomplished by a Perkin Elmer 7500 dedicated computer system using PHI software package. 

The reaction of trans- [Rh(PR3)2Cl(CO)] with methyl iodide was studied by monitoring the IR spectra of solutions of the complex (2 x 10-2 mol L"1) in methyl iodide (redistilled) in a thermostatted solution IR cell provided with sodium chloride windows. A Perkin-Elmer model 577 spectrometer was used. The data was analyzed using the FACSIMILE computer program (14). 

The mass spectrum of cimetidine using a Hitachi Perkin-Elmer PMU-7E medium resolution mass spectrometer and a direct insertion probe of the sartple is shown in Figure 6. The mass spectrum was recorded on magnetic tape and relative abundances were calculated with a PDP-8/I digital computer coupled to the instrument. The results are presented in tabulated form in Table 2. ... 

Spectrophotometry. Infrared spectra were obtained with a Perkin Elmer Model 281B Spectrophotometer interfaced with a computer data station. Films were encased in sample holders in the reference beam, and spectra were obtained with air as reference. The spectra were scanned from 1900 - 1500 cm-l at a scanning time of 60 minutes with a response setting of 2. The slit program was set at N. All spectra were recorded on computer disks. 

All the solid phases were identified and characterized for crystallinity by X-ray powder diffraction (Philips PW 1730/10 diffractometer, Cu Kq radiation equipped with a PW 1030/70 vertical goniometer and connected to a P.C. computer for quantitative analyses). Crystallinities for Nu-10 and cristobalite were computed by comparing the intensity of the most characteristic diffraction peaks of each sample to that of the corresponding pure 100% crystalline phases used as standards. In some cases calibration curves derived from Nu-10/cristobalite mechanical mixtures were used. Si, Al, and alkali contents were determined either on precursors or calcined samples (900 C, air flow, 4h) by atomic absorption, using a Perkin-Elmer 380 AA instrument after digestion and dissolution of the samples in H,S04/HF solutions and further elimination of HF by gentle heating at 60 C for 12 n. 

Perkin Elmer MPF-3 spectrofluorometer. X- and Q-band measurements of EPR spectra were carried out at liquid nitrogen and liquid helium temperatures. Microcalorimetric measurements were performed on a LKB 10700 batch microcalorimeter. Temperature-jump relaxation kinetics were measured using a double beam instrument (18) with a cell adapted for anaerobic work. The relaxation signals were fed into an H.P. 2100 computer and analyzed as described in Ref. 7. The pulse radiolysis exepriments were carried out on the 5-MeV linear accelerator at the Hebrew University. Details of the system have been published previously (19). 

At present, the manufacturers listed below deliver reliable instruments with satisfactory working software. The type of instruments and models are not listed because the models change frequently and the software is updated almost annually. Users may select from a variety of beam splitters, detectors, computer memory, and software. The entire spectral range, from the far infrared through the near infrared, is covered by various FTIR instruments. Instrument suppliers include Analect (USA), Bomem (Canada), Bruker (FRG), Bio-Rad, Digilab Division (USA), Mattson (USA), Jasco (Japan), Nicolet (USA), and Perkin-Elmer (UK). Accessory manufacturers include Spectra-Tech Inc. (USA), Specac (UK, USA), Harrick Scientific Corp. (USA), and AAB SPEC (USA). 

Instrumental Conditions. FAA analyses for Ba, Fe, and Mn were done on a Perkin Elmer model 560 atomic absorption spectrophotometer with an air-acetylene flame for Fe and Mn and a nitrous oxide-acetylene flame for Ba (38, 39), The remaining elements were determined by ETAA with the conditions listed in the appendix (Table A-l) with a Perkin Elmer model 5000 atomic absorption spectrophotometer equipped with a model HGA-400 graphite furnace and a deuterium background corrector. The precision of FAA was 1.0% and the precision of ETAA was 10%. Absorbance readings for FAA were converted directly to concentrations by comparison with absorbance readings for standards that had been previously stored in the instrument s computer. 

IR Spectroscopy. Samples for IR spectroscopy were prepared by pressing 100-mg KBr pellets containing 1 mg of sample. Samples were run both on a Perkin-Elmer model 167 dispersive (grating) instrument and on a Perkin-Elmer model 1750 Fourier transform diffractometer-model 7300 laboratory computer system. Only the latter instrument afforded the resolution needed to identify the skeletal frequencies of isopropyl groups. 

International cooperation had become the rule in universities and research institutions. Computers became cheaper so that it became possible to purchase minicomputers such as VAX 11/780 (Digital Equipment Corporation), Perkin-Elmer 8/32, or Convex C220 for dedicated purposes. For a number of theoretical chemistry groups, this helped them to become independent of the long queue of users at their university central computer. In addition, access over a network to machines at a remote site became realistic, even if it was only via a 1200-baud special telephone line. For these reasons the... 

An acid extraction was prepared on all samples and was carried out in the manner described later. After extraction, all samples were filtered with 0.45-/zm fluorocarbon filters. Twenty microliters of solution was used for each analysis on a Perkin-Elmer series 10 HPLC. Each sample was allowed to run 20 min, and the results were printed by computer. The column used was a 10-cm C-18 reverse-phase 10-/zm Perkin-Elmer column with an Alltech precolumn attached. The detector used was a Perkin-Elmer model LC-15 UV detector set at 254 nm. 

Analytical Report from Computer Data Processing Courtesy of the Perkin Elmer Corporation... 

The GC-MS computer system consists of a Perkin-Elmer 990 gas chromatograph interfaced to a Hitachi RMU-6L mass spectrometer which is in turn interfaced to an IBM 1802 computer. The details of this hardware and associated software have been published previously (2). The HRMS system consists of a DuPont Instruments 21-llOB mass spectrometer and a D. W. Mann comparator interfaced to the IBM 1802 computer. Details on this system are available elsewhere (3). Both mass spectrometers were operated at 70 eV ionizing energy. 

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