HPLC and UHPLC

Brian C. Smith, PhD, is Founder, CEO, and Chief Technical Officer of Big Sur Scientific. He is the inventor of the BSS series of patented mid-infrared based cannabis analyzers. Dr. Smith has done pioneering research and published numerous peer-reviewed papers on the application of mid-infrared spectroscopy to cannabis analysis, and sits on the editorial board of Cannabis Science and Technology. He has worked as a laboratory director for a cannabis extractor, as an analytical chemist for Waters Associates and PerkinElmer, and as an analytical instrument salesperson. He has more than 30 years of experience in chemical analysis and has written three books on the subject. Dr. Smith earned his PhD on physical chemistry from Dartmouth College. Direct correspondence to: 

Articles

A review of the concept of separation factors and a discussion on developing a method for measuring peak width including triangulation followed by the introduction of the concept of chromatographic resolution for a pair of peaks.

Chromatographic Theory, Part V: Chromatographic Resolution

The current challenges and future perspectives of the purification of cannabinoids from cannabis extracts are presented in this review article.

Purification and Isolation of Cannabinoids: Current Challenges and Perspectives

Part IV of this series discusses the capacity factor of chromatographic peaks to calculate separation factors, whose value tells us how well two peaks are or aren’t separated. We then introduce the reality of peak widths and how they impact separation quality.

Chromatographic Theory, Part IV:  Measuring Separation Quality with Capacity and Separation Factors

Part III of this series will delve into understanding how to optimize methods for chromatographic separations, Smith will also introduce the concepts of capacity factor and selectivity.


Chromatography Theory, Part III: Calculating Elution Times and Capacity Factors

Part II of this series looks at the mechanism via which molecules move through HPLC columns and leads us to a discussion on the equations used to characterize separations.

Chromatography Theory,  Part II: How Separations Occur Illustrated and Quantitated

The final part in this series of pitfalls to avoid and practicalities covers the importance of cleanliness, how many standards to run, how to spot outliers, and important experimental variables to control.

Quantitative Spectroscopy Pitfalls and Practicalities, Part IV: The Finale

The third part in this series of pitfalls to avoid and practicalities to know about discusses the importance of validating and checking your calibration to ensure quality.

Quantitative Spectroscopy Pitfalls and Practicalities, Part III:  Calibration Validation and Calibration Checks

Part II of this series discusses how to measure absorbances properly, and compares the use of peak heights and peak areas in creating calibrations.

Quantitative Spectroscopy: Practicalities and Pitfalls, Part II

is a Full Professor and Shimadzu Distinguished Professor of Analytical Chemistry in the Department of Chemistry & Biochemistry at The University of Texas (UT) at Arlington.

In the work presented here, the authors evaluated the effects of variable red-light exposure on the phytochemical content of four Group III cannabis cultivars.

Variable Red Light Exposure Affects Phytochemical Content  in Group III Cannabis Cultivars

Here we discuss the importance of using standards that bracket the expected concentration range of standards in the unknowns, using the same chemical components in standards and unknowns, and making sure to minimize the error in concentration measurements of standards.