{"id":7313,"date":"2020-05-04T08:09:40","date_gmt":"2020-05-04T15:09:40","guid":{"rendered":"https:\/\/www.vernier.com\/til\/?p=7313&preview=true&preview_id=7313"},"modified":"2024-10-17T06:46:32","modified_gmt":"2024-10-17T13:46:32","slug":"how-is-the-go-direct-mini-gc-different-than-previous-versions-of-the-mini-g","status":"publish","type":"post","link":"https:\/\/www.vernier.com\/til\/7313","title":{"rendered":"How is the Go Direct Mini GC different than previous versions of the Mini GC?"},"content":{"rendered":"

In March of 2020, Go Direct®<\/sup> Mini GC™<\/sup><\/a> (GDX-GC<\/nobr>) replaced the Vernier Mini GC Plus<\/a> (GC2-MINI<\/nobr>).<\/p>\n

There are several differences between the Go Direct Mini GC and the Mini GC Plus. There is a new column and new detector in the Go Direct version; this allows it to detect more compounds as well as show more classic gaussian GC peaks.<\/p>\n

Key Similarities:<\/strong>
\n1. Both can be connected via USB to a computer (using Instrumental Analysis), LabQuest 2 or LabQuest 3 (using LabQuest App), or Chromebook (using Instrumental Analysis).
\n2. The GDX-GC can be used to complete any of the previous experiments written for Vernier gas chromatographs, including those from Organic Chemistry with Vernier.\u00a0<\/a>
\n3. All Vernier gas chromatographs use the same power supply, syringe, and septa.
\n4. All Vernier gas chromatographs are compatible with the free Instrumental Analysis software.<\/p>\n

Key Differences:<\/strong>
\n1. The GDX-GC has Bluetooth so it can transmit wirelessly directly to tablets, phones and other devices (the GC2-MINI cannot do this).
\n2. The Go Direct Mini GC can detect significantly more chemicals than the Mini GC or Mini GC Plus did. Most notably, it can detect nonpolar compounds, including hydrocarbons. The complete list of compatible compounds is available on the product\u00a0webpage<\/a>. You can also view sample chromatograms for the Go Direct Mini GC here.\u00a0<\/a>
\n3. The GDX-GC does not work with Logger Pro<\/i>. It only works with LabQuest 2, LabQuest 3, or with Instrumental Analysis software.<\/a>
\n4. It comes with five brand new experiments to help users explore the new compounds it can detect.
\n5. The detector in the Go Direct Mini GC<\/strong> is resistance-based, meaning resistance increases with temperature, causing baseline drift near zero. To address this:<\/p>\n

    \n
  1. Pay attention to the Y-Axis<\/strong>: Your sample data has low amplitude, making the non-zero baseline more prominent. Try increasing the sample volume or adjusting the temperature\/pressure profile.<\/li>\n
  2. Switch to an Isothermal Profile<\/strong>: If you’re measuring one compound, there\u2019s no need for a temperature ramp, which can amplify drift. Use a ramp only if necessary for separating mixtures.<\/li>\n
  3. Subtract the Baseline<\/strong>: Since this is electronic noise, baseline subtraction will improve data accuracy.<\/li>\n<\/ol>\n

    6. The Go Direct Mini GC<\/strong> has a different detector and column than the Mini GC or Mini GC Plus, enabling it to detect more compounds. As a result, even with the same sample and temperature\/pressure profile, chromatograms will show different peak heights and retention times between devices. To optimize results:<\/p>\n