Author Archive

A closer look at selectivity and tailing: Essential oils and Wax phases

The most common way to analyze essential oils is to use GC with either a FID or MS. The wax-based columns are the number one choice for many users and following up on an excellent blog post by Corby, I wanted to evaluate two wax in Restek inventory: Stabilwax and Rtx-Wax. The essential oil we chose was […]

Analyzing orange: peel and pulp separately or as whole?

Up to this point, I’ve focused on the optimization of QuEChERS salts and dSPE cleanup with fairly homogenous matrices. So, what about oranges? Should I peel them and analyze only the pulp? After all, that is the edible part. The peel is used as well – pressed into essential oils or scraped into zest. Besides, […]

What dSPE works with spinach in GC-MS/MS analysis? #NationalSpinachDay

Today is a National Spinach Day! What is a better way to celebrate than to talk about spinach analysis? During part 1 of my blog series, I discussed what dSPE was best for celery. I found that most dSPE, with the exception of dSPE containing high amounts of graphitized carbon black (GBC), showed acceptable analyte recovery […]

3-MCPD blog part 2: How hot we can go with inlet and can we use regular split/splitless inlet?

In my last blog, I (hopefully!) made a case that switching to split injection for analysis of 3-MCPD esters is a viable option. Now I’d like to show that if we stick to split, we can also use much higher temperatures and if we can do that, we can also use regular split/splitless inlet. To […]

Choosing the right dispersive SPE for GC-MS/MS analysis of celery

I’ve recently started experimenting with QuEChERS extractions for pesticide analysis. The available options are overwhelming, especially when it comes to dispersive solid phase extraction (dSPE) for the cleanup. For starters, I’ve been looking at the smaller volume dSPE (2 mL, summarized in Table 1), because I didn’t want to waste the raw material, solvents and […]

Trade in Splitless for Split: Faster Speed & More Miles Analyzing 3-MCPD / Glycidyl esters

In my recent work with analysis of 3-MCPD and glycidyl esters, I reviewed the available methods by AOCS and they list splitless or pulsed splitless injection. Splitless injection theoretically transfers all of the sample onto the column, allowing the analyst to achieve trace levels of detection. However, there are limitations. Both splitless hold-time and focusing […]

FAMEs blog part 4: Struggling with using hydrogen for AOCS methods Ce 1j-07 or Ce 1h-05?

This blog a part of a series: part 1, part 2, and part 3 Recently I came across customers’ issue with AOCS method Ce 1h-05 used with hydrogen as a carrier gas and I’ve decided to look more closely into what conditions are suggested for this analysis. While at it, I looked also into conditions of methods […]

FAMEs blog part 3: If I Use a Rt-2560 with my GC-MS will it explode?

This blog a part of a series: part 1, part 2, and part 4 Disclaimer: Do not use non-bonded columns, such as Rt-2560, in GC-MS for routine analysis! If you have the need to run some samples, here is what to expect (i.e. quite a bit of bleed) In my last blog, I talked about how […]

Trans fatty acids analysis part 2: Let’s look at actual samples with incurred TFAs

This blog a part of a series: part 1, part 3, and part 4 In my previous blog, I’ve tried and failed to acquire a sample that contained any trans fatty acids (TFAs). While this is a great news for everyone’s health, the scientist in me was somewhat disappointed. That’s why I first decided to cheat […]

The main source of artificial trans fatty acids is banned on June 18, 2018. Are we ready?

This blog a part of a series: part 2, part 3, and part 4 One of the leading causes of deaths in the world is heart disease, accounting for approximately 24% of deaths in the USA in 2015.1 One of the factors linked to cardiovascular diseases is consumption of artificial trans fatty acids (TFAs). Artificial TFAs are […]