Archive for the ‘Packed Columns’ Category

Maximum temperatures of packed columns – Sulfur Gases

For my fifth and final post in this series, I would like to focus on packed columns for light sulfur gases.  Compounds include (but not limited to) hydrogen sulfide, sulfur hexafluoride, carbonyl sulfide, sulfur dioxide, methyl mercaptan, ethyl mercaptan, etc. Because some analysts prefer PTFE tubing and/or PTFE frits for their columns, the maximum temperature […]

Maximum temperatures of packed columns – Molecular Sieves

For my forth post in this series, I would like to focus on molecular sieve packed columns.   At Restek, our three most common molecular sieve packings are the ShinCarbon, 5A, and 13X.  The ShinCarbon is a carbon molecular sieve, while the 5A and 13X are zeolite molecular sieves.  To read more about these packings/columns, please […]

Maximum temperatures of packed columns – Hydrocarbon Analysis

For my third post in this series, I would like to focus on specialty packed columns for hydrocarbon analysis.  In some cases, the packings in these columns are proprietary, so detailed information cannot be provided.  In other cases, application information may be limited.  However, we can provide maximum temperature limits (see table below). For other […]

Maximum temperatures of packed columns – Liquid Phases

For my second post in this series, I would like to focus on liquid phases.  As you know, for packed columns, a liquid phase needs a solid support.  Combined, these are what makes the “packing”.  In most cases, it is the liquid phase which limits the packed column’s maximum temperature, and not the solid support. […]

Maximum temperatures of packed columns – Porous Polymers

We often get asked about the maximum temperature limit of our packed columns, so I decided to write a post series which will provide this information for the majority of the packed columns which we sell.  I thought I would start with the least complicated packed columns, those whose packings are typically not coated with a […]

Packed Column information for the beginner

We seem to be getting more calls from first time users of packed columns, so I decided to write this post for these beginners to help them understand the terminology commonly used when describing these products.   What is a packed column? Unlike GC capillary columns, which are referred to as WCOT (Wall Coated Open […]

GC columns – when one is not enough

Often we get asked for a column recommendation for a complex GC analysis.   This is especially true for gas analysis.  Probably the most common request is for separation of fixed (permanent) gases (like O2, N2, CO, CO2, N2O, etc…) plus separation of larger (higher-boiling point) compounds (light hydrocarbons, moisture, sulfur compounds, etc.).  Unfortunately, there is […]

Think twice before purchasing a 3/16” OD packed column

So you may be asking yourself, why the cautionary statement? Well, it’s very simple, many of our customers who purchase 3/16” OD (outside diameter) packed columns have a difficult time installing them into their GC oven.  Why?  Sometimes finding the appropriate fitting/ferrule is difficult. Let’s say you have a packed column instrument. If your injection port […]

Verify your GC packed/micropacked column carrier gas flow to obtain reproducible results

Working in technical service has taught me many things, but one of the most important has been “don’t assume anything”. This is especially relevant when it comes to verifying the carrier gas flow through GC columns.  To obtain reproducible results from column to column, this verification should always be done after installing a different packed/micropacked […]

Understanding packed column mesh size ranges

If you have ever ordered a packed column, you are aware that mesh size of the solid support (packing) is one of the specifications you will need to know.  But have you ever wondered what mesh size actually means? To find the answer, let’s look at the products and process.  The necessary products are ASTM […]