20200729_GC_Purchase_Statement submitted.doc

Gas Chromatograph Purchase Statement prepared for INSERT NAME, by Dr. Dana Miles 662-285-7659 And Frances Podrebarac 812-447-7674 cell 29 July 2020 The U.S. Department of Agriculture, Agricultural Research Service, intends to buy a greenhouse gas analyzer which uses gas chromatography (GC) to analyze atmospheric samples for nitrous oxide, methane, and carbon dioxide.

Description of Supplies/Services required to meet the Agency’s Needs: The greenhouse gas analyzer complete with accessories must be equivalent to the Scion Instruments Greenhouse Gas Analyzer and compatible with the following: CombiPal Headspace Autosampler, CompassCDS software, OptiPlex 3070 computer (Windows 10 Pro), monitor, and printer. Compatibility is of utmost importance since these items (CombiPal Headspace Autosampler, CompassCDS software, OptiPlex 3070 computer (Windows 10 Pro), monitor, and printer) are already owned and will not be purchased. In addition, include Installation, familiarization, and method development within the full system. The application requires the GC to be configured to analyze atmospheric samples for nitrous oxide, methane, and carbon dioxide on the same sample. Other atmospheric constituents must not interfere with the analyses and the machine must be able to detect nitrous oxide from 50 ppb to 100 ppm, methane from 0.1 ppm to 1% and carbon dioxide from 1 ppm to 10% with a residual standard deviation (RSD) of < 2% for each gas. The machine must be able to allow both autosampling and manual sample injection. The installation training includes 6 hours of on-site training at the time of installation.

The company must provide methods development that includes optimization of conditions of the autosampler, purge timing and duration, backflush timing and duration, column oven temperature programming, flow rate determination, and detector settings. The GC configuration can be easily adjusted for other applications (i.e. to measure oxygen at the low concentrations-below 100 ppm) but oxygen does not interfere with nitrous oxide measurements under the standard configuration. In addition, the GC provides a custom manual and on-site demonstration of calibration curves for all three gases of interest in their respective concentration ranges.

The laboratory room conditions in which the system must operate includes temperatures up to 40 °C and relative humidity up to 95 %.

Additional specifications for the autosampler and computer:

Again, these items are on hand and will not be purchased.

The current autosampler accommodates liquid and headspace injections, includes a mounting kit, and tray holder for 1, 2, and 10 mL vials. Sample tray with 200 (1 mL) vial capacity is included.

The software that interfaces and controls the GC must include CD-ROM(s) with manuals in Adobe Acrobat format, provide full instrument control and method download for GC with autosampler, and runs under Windows 10 Pro. The GC must be compatible with Dell Optiplex 3070 Minitower with Intel Core i3 (3.6 GHz) processor, 4.0 GB of RAM, 3.5”500GB 7200RPM SATA Hard Drive Disk, Intel Integrated Graphics video card, 8x DVD DVD+/-RW 9.5 mm Optical Disk Drive, USB 2. Ports (2 front, 2 rear), USB 3.1 Gen 1 Type-A Ports (2 front, 2 rear), HDMI Port (1 rear), VGA 15-pin (1 rear) and Windows 10 Pro.