ANALYTICAL
32 A
CHEMISTRY
NEW PRODUCTS, continued
In operation, fume-laden air is drawn into the tower through the large air intake, and sucked up through the intermediate sections filled with packing. Water admitted at normal city line pressure is sprayed over the packing by the spraytight distributor. As air rises in the tower, it is scrubbed thoroughly by the descending water which absorbs the fume content. Washed air dis charging from the top exhaust duct is released into the room directly, or through suitably prepared duct work. Waste water leaves the tower through the drain. 10 Labeled Compounds
FP££
TO ANALYTICAL CHEMISTS If you are an analytical chemist, this handy, desk-size S&S Filtra tion C h a r t belongs in your laboratory. Analytical laboratories have long been familiar with standardized, high-quality S&S Analytical Filter Papers. Now, here is complete data on the relative retention values of S&S Analytical Filter Papers, and other brands, in convenient size for ready reference. This data makes it possible to tell at a glance which grade of paper to select for a given analysis. Send for your valuable, free S&S Filtration Chart. Act now! Use the handy coupon below! S & S ULTRA FILTERS
S&S dual-purpose ultra filters — smooth-surfaced membranes pos sessing extremely uniform microstructure—are ideal for filtration of colloids, proteins, and micro-organ isms, as well as dialysis and osmosis. "Mail coupon below for your free S&S Ultra Filter Catalog. MAIL
THIS
COUPON
TODAY
CARL SCHLEICHER & SCHUELL CO. Dept. A-7, KEENE, NEW HAMPSHIRE
Send me your FREE • S&S Filtration Chart Π S&S Ultra Filter Catalog Name Company Address _State_ City
Tracerlab has several new carbon-14 labeled compounds which will aid chemists working on monomolecular layer studies, flotation studies, and re search in the soap and oil fields. The following compounds, each with a spe cific activity of 1.0 millicurie per millimole, are available: laurio acid-1carbon-14 (L4-22) and stearic acid-1carbon-14 (L4-23). Another recent addition is di-aspartic acid-4-14 (L5-15) with a specific activity of 0.5 to 1.0 millicurie per millimole. Minimum order is 0.1 millicurie. 11 Diffusion Pump
Will Corp. has designed a new model diffusion pump whose special features are: economical use of pumping fluids, speed of operation, and ability to operate at a high forepressure. Used in con junction with inex pensive mechanical vacuum pumps, it will reach an ultimate vacuum of 5 X 10 ~6 mm. of mercury while operating with a forepressure of 5 mm. of mercury. Volume of pumping fluid re quired for operation is 12 ml. The system requires only a 4-minute warmup period before it is in full operation. Cooling water required is 0.1 gram per minute. All vacuum connections are slip fit rubber tubing. The pump is operated from a standard 110-volt, 60-cycle electrical outlet. 12 Filter Pumps
Sethco Manufacturing Co. has two new models of filter pumps for filtering corrosive solutions: one with rated capacity of 50 gallons per hour and the other with a rated capacity of 100 gallons per hour. These pumps will filter almost any acid or alkaline solu
tion from pH 0 to pH 14 or nonaqueous solutions. The filter will remove par ticles down to 1 micron in size but the strainer stops metallic objects. These pumps are self-priming and have suction lifts of approximately 15 feet. The filter assemblies are fabricated of high temperature lucite and are also available in other materials. The filter tubes are made in cotton, Dynel, porous stone, or porous carbon. The yarn is wound around a stainless steel support ing core or perforated bakélite tube to give a 3/4-inch thick wall of interlaced filtering cylinders. Channeling or rupturing is eliminated by the heavy wall of yarn surrounding the core. Filtration is in depth; it is not a surface operation. The size of particles to be filtered out can be controlled from 150 microns down to 1 micron by varying the dens e r of the mesh of cotton or Dynel wound on the supporting core. 13 Back-Up Rings
The Garlock Packing Co. has designed back-up rings, spirally machined of tetrafluoroethylene, to prevent extrusion of Orings. The Teflon rings have a high impact strength at temperatures from — 100° to +500° F. They are noncorrosive, nonadhering, nonfraying, inert to most chemicals, and self-lubricating. They are made for all O-ring sizes. 14 Reagents
Fisher Scientific Co. has announced the availability of three new reagents: (1) certified reagent grade primary m-amyl alcohol; (2) certified reagent grade Devarda's metal in a special lownitrogen form in which no individual analysis exceeds 0.005% nitrogen; and (3) a low-nitrogen (0.005% nitrogen maximum) selenium metal for Kjeldahl determinations. 15 Test Chambers
Murphy & Miller, Inc., has introduced a new line of multirange, allpurpose test chambers capable of producing low temperatures to —130° F., high temperatures to 200° F., and a standard humidity cycle of 20 to 95% from + 3 5 ° to +185° F . The chambers are made in 5 sizes with test space capacity from 4 to 36 cubic feet. A high capacity, low velocity forced air circulation system provided by a fan whose motor is mounted outside the For further information, see coupon on page 29 A
