HPLC 3 MORE INNOVATIONS FROM VALCO... DESIGNERS AND MANUFACTURERS OF THE WORLD'S MOST WIDELY USED HPLC INJECTION VALVE • OVER 15,000 SOLD.

SUBMICROLITER INJECTOR FOR HPLC * 0.2, 0.5 or 1.0 μ I volumes

available • 5000 psi rated-higher

pressure ratings available Automatic actuation,

air/electronic or electric/electronic

Permits direct coupling to y16" columns with frit in outlet port

• Outlet port is .010" for minimum band-spreading

* See the MICROBORE publications by Scott and Kucera, J. CHROM., 169, 51, (1979), and Scott and Simpson, Pittsburgh Conference, March 1981, #756.

FOUR COLUMN SELECTION VALVE

• Permits up to four columns to be mounted on one valve • If three columns only are installed, solvent change over

position is available Automatic opera­tion, air with electronic interface or all electric 5000 psi rated

• Cited in "Hardware Components" of an Automatic HPLC System", Varghese, Holmes, and Martin, Pittsburgh Conference, March 1981,#798

10-PORT MULTIFUNCTIONAL

INJECTION-SWITCHING VALVE

Uses standard HPLC syringes without waste (optional)

* Combines two functions into one valve with reduction of band spreading caused by tubing and connections Typical examples include:

•sample injection followed by backflush of one column

•sample injection into two columns simultaneously

•sample injection (random access] into either of two columns

•sample injection followed by backflush of precolumn

•trace enrichment •sample injection followed by backflush to vent of precolumn

•alternate sample injection from two streams

•two column selection with maintained flow on both columns

Manual or automatic operation (either air or electric) Costs little more than a standard 6-port valve

* Cited in "Sample Injection and Column Switching Using a Multi­functional Valve", Harvey and Stearns, American Laboratory, March 1981 issue, and Pittsburgh Conference, March 1981, #548

Opening Soon V I C I A G (Valco Switzerland) in Schenkon, Switzerland. S e e V a l c o P r o d u c t s at the fo l lowing c o n f e r e n c e s : LABCON '81, Chicago, Ill., booth 404 ILMAC '81, Basle, Switzerland, Hall 27, booth,651 HET INSTRUMENT, Amsterdam, Nether lands, booth R-7

VICI Valco Instruments Co. Inc. P.O. Box 55603 Houston.Texas 77055 (713) 688-9345 TWX 910-881-5550 Telex 79-0033

ANALYTICAL CHEMISTRY, VOL. 53, NO. 9, AUGUST 1981 · 1115 A

CIRCLE 220 for information on submicroliter injectors

CIRCLE 221 for information on four column selection valves CIRCLE 222 for information on 10-port valves