NEW required reading
this metering p u m p is cheaper by t h e half-dozen
from Waters — the Liquid Chromatography People
Not only is the Ace Micropump Series 2 available with high-accuracy outputs from 4.5 ml/hr to 3000 ml/hr, but it will drive up to six modular add-on pumpheads—economically. The following prices tell the story: One pumphead :$ 723 Two pumpheads : $ 1 0 5 6 Three pumpheads :$ 1389
LC Packing Materials and Packed Columns Catalog. A complete descriptive price list of Waters Associates' wide selection of column packing materials for high speed/high resolution chromatography. Ask for DS013.
Four pumpheads :$ 1722 Five pumpheads :$ 2055 Six pumpheads : $ 2388
Pressures? Up to 1000 psi. Availability? From Stock. Accuracy? Within 1%. Need more data? Write or call.
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Ace Industrial Division P.O. Box 127, Linden, New Jersey 07036. (201)925-3300.
CIRCLE 244 ON READER SERVICE CARD
CIRCLE 319 ON READER SERVICE CARD
Separation and Identification of Nucleic Acid Constituents. 4 pgs. Describes the LC separation of DNA and RNA and their constituents — purine and pyrimidine bases, nucleosides and mononucleotides. Ask for AN 147.
How to get maximum reliability from low cost electron multipliers. Typical Box-and-Grid Structures
CIRCLE 320 ON READER SERVICE CARD
Overall Voltage (kV)
There's no need to pay top dollar for mass spectrometry electron multipliers. DuMont SPM structures are tolerant of air exposure and of operation at pressures of 10 5 and 10 6 Torr for extended periods. They are available in sealed glass envelopes with either Venetian blind or box-and-grid high-stability B e - C u d y n o d e s w i t h 10, 1 2 , 1 4 , 1 6 , 1 8 or more stages. The chart shows current amplification versus applied voltage for boxand-grid structures. Maximum anode current is on the orderof 100 microamperes. Signal-to-noise ratios for single particle detection is very high. Typical applications for DuMont SPMs are mass spectrometry,-gas chromatography, X-ray counters and vacuum UVdetectors. For prompt information phone or write: 750 Bloomfield Avenue, Clifton, New Jersey 07015. • | j f n Q n t
A subsidiary ol THOMSON-CSF ( 2 0 1 ) 7 7 3 - 2 0 0 0 . Marketed outside North America by THOMSON-CSF Groupement Tubes Electroniques/PARIS. CIRCLE 417 ON READER SERVICE CARD LABORATORY GUIDE
Molecular Weight Distribution of Polymers.
A NEW WAV TO TELL GOOD F R O M BAO
New Way to Tell Good from Bad. This 12 pg. brochure describes various exclusion chromatography methods used to characterize rubber, paints, resins, oil and other complex polymer materials. Ask for AN 163.
CIRCLE 321 ON READER SERVICE CARD
free from WATERS ASSOCIATES 131 Maple Street, Milford, Ma 01757 Telephone (617)478-2000 The Liquid Chromatography People AUGUST 1975 155 LG