A basic understanding of gas flow principles is fundamental to obtaining accurate flow measurements. This primer contrasts mass flow and volumetric flow regimes, and illustrates the effect of flow impedance and loading on the flow source in gas chromatography.
Proper conditioning is essential for optimal performance from a capillary GC column, but inexperienced chromatographers might not know the proper procedures for installing and conditioning a new column. Here, we summarize our recommendations for installation and conditioning procedures.
Recovery of a 17 ppbv test standard of hydrogen sulfide exceeded 85% after 54 hours in a Sulfinert-treated cylinder; recoveries of methyl mercaptan, ethyl mercaptan, carbonyl sulfide, and dimethyl disulfide exceeded 90%. A Sulfinert-treated sampling/transfer system can assure accurate sulfur content data for natural gas, beverage-grade carbon dioxide, or other samples.
The analysis of synthetic cannabinoids and their metabolites can be a difficult and challenging task. Keeping up with the ever-growing list of synthetic cannabinoids that illicit drugmakers produce further complicates the analysis. As shown here, the retention and selectivity of the Raptor Biphenyl column allows new drugs to be added to an existing method, providing labs with an important vehicle for improving efficiency and productivity.
LC-MS/MS analysis of EtG and EtS is challenging due primarily to poor retention and resolution of EtG and EtS from matrix components. This article presents a foundation method that is useful for many samples and also demonstrates effective strategies for improving sensitivity and mitigating matrix effects.
As the demand for testing of pain management drugs increases, many laboratories are turning to LC-MS/MS for its increased speed, sensitivity, and specificity. The methods shown here use a Raptor Biphenyl column because it provides fast, accurate analysis of 231 drugs and drug metabolites.
A new LC-MS/MS method for methylmalonic acid (MMA) analysis was developed that provides complete chromatographic resolution from isobaric succinic acid in plasma samples. Excellent chromatographic results were obtained from the direct injection of a protein crash sample supernatant onto a Force C18 column, providing a much simpler sample preparation compared to typical methods.
Sometimes customers need to analyze natural gas and petroleum products, whether it is to confirm the purity of the product by looking for the impurities which may be present, or for an environmental reason such as a spill or leak….
If you use the correct fittings and seals in the gas chromatography system, and follow some simple steps, there is absolutely no need to over tighten any fitting to achieve a leak free seal. For almost all fittings that use…
As we approach the end of the year we are indulging in a bit of nostalgia and most experts agree that reminiscing about the past is a good thing1. It makes us more optimistic and generous. Researchers also noticed that…
