LITERATURE
ICP-AES of brines
Application note No. 84 describes the use ESIMS of the U-5000AT" ultrasonic nebulizer in Application note No. 212 describes a maxi- combination with the HST-100 high-solids mum entropy program for simplifying torch for direct ICP-AES of seawater. ESI mass spectra of complex mixtures that The nebulizer and the torch reduce cloghas been incorporated into the VG Massging for improved detection limits and preLynx software package. The note explains cision. Detection limits and % RSD are how the MaxEnt feature transforms each presented for eight elements. Cetac multiply-charged ion series into a single • 417 peak on a molecular weight scale. Fisons • 415 HPLC HPLC Application Handbook presents 270 HPLC application chromatograms and 175 refBrochure describes five HPLC method erences for 1200 compounds. A methods development kits for general, pharmaceu- section includes tips on column and motical, biotechnology, and chiral separabile phase selection, control of analyte tions. Surface chemistries are described retention, and detector selection. Samples for each of the columns in each kit. and compounds are indexed alphabetiPhenomenex 1 4 1 6 cally. Hamilton B418
Spectrophotometry w i t h array d e t e c t i o n The S-2000 Series UV-vis spectrophotometers incorporate silicon photodiode array detectors for spectral acquisition and an interface card and software for control through a standard PC. The four models are designed to operate in the wavelength ranges of 190-1065 nm or 190-800 nm with either 512- or 1024-channel detectors. Diode array detection allows for full-spectrum scans in < 10 ms or integration of weak signals for up to 52 s. It also provides wavelength accuracy to ± 0.3 nm and reproducibility of ± 0.05 nm for photometric accuracy of ± 0.005 AU. Intensities can be measured on the sides of peaks in cases where interferences obscure the peak maximum or the peak goes off scale. To take advantage of the detectors' simultaneous acquisition of multiple wavelengths, the deuterium arc UV source and the tungsten visible light source operate simultaneously. The spectrophotometer interface card, which fits any PC with at least a 386 CPU and an available standard AT
slot, allows for keyboard or mousebased control and data display. System software performs single-component quantitation or multicomponent analysis and allows the use of multiple standards with different wavelength ranges and integration times to calculate kinetic rate constants. The software also performs self-diagnostic verification. Accessories for the S-2000 spectrometers include an autosampler, a temperature-controlled single cell holder, an eight-cell sample changer, external cell-temperature controllers for heating or cooling, flow cells, and stirred cells. Scinco 1 4 1 9
M u l t i m e d i a FT-IR The «-Series FT-IR microspectroscopy system incorporates interactive Windows-based multimedia technology and allows users to interact directly with a video image of the sample on the PC screen. Other IR microscopy systems are based either on a modified optical microscope design or on an IR beam condenser modified to provide viewing capabilities and may compromise some spectroscopic sensitivity or visual image quality. The interactive system consists of an FT-IR microscope, an FT-IR spectrometer, and an automated graphic environment designed for IR microspectroscopy. Permanently aligned cassegrain optics are provided for high IR sensitivity and a working distance of > 20 mm; they ensure that the visual and IR images remain permanently aligned. Research-grade microscope optics and built-in variable illumination enhance visual images for binocular or video viewing. The multimedia software system controls a motorized microscope stage and provides interactive control of data collection. By marking the visible image displayed on screen, the user can program the system to scan a series of sample points or produce a complete IR image. The display is updated in real time for spectral acquisition and progress across the sample. IR image types include total absorbance, single wavenumber, absorbance band ratio, and functional group images. Perkin Elmer • 420
Analytical Chemistry, Vol. 67, No. 9, May 1, 1995 3 2 9 A
