Author Archive

Upcoming revisions to three wastewater methods reviewed at NEMC 2017

Monday morning, representatives from the EPA’s wastewater office reviewed the significant changes for the three major GC wastewater methods: 608.3, 624.1, and 625.1. The overarching goals were to modernize the methods and bring the language and QC requirements in line with the methods from the drinking water and hazardous waste offices. The methods have been […]

Troubleshooting Injection Volume Variation in the Concurrent Solvent Recondensation – Large Volume Sample Injection Technique

I’ve started receiving a number of questions about the large volume injection technique called Concurrent Solvent Recondensation – Large Volume Sample Injection. Most recently, a question came through the Tech Service group about injection volume variation. I had encountered a similar problem when working on the 50 µL injection for the combined 1,4-Dioxane and Nitrosamines (EPA […]

New Custom UCMR4 Standard for EPA Method 530 on the Rxi-5Sil MS

We recently stocked custom EPA Method 530 standards made specifically for labs participating in Unregulated Contaminant Monitoring Rule 4 (UCMR4). Quantitative Certificates of Analysis with Data Packs are available for each item. Email csreps@restek.com or phone 800-356-1688 ext. 3 to place your order (items are not available at Restek.com). EPA Method 530, the Determination of Select Semivolatile […]

EPA Method 541 on the Stabilwax Column

I recently posted some chromatograms for our new EPA Method 541 UCMR4 Standards, and wanted to focus on the column in a separate post. EPA Method 541 was developed on a 30m x 0.25 mm ID x 0.50 µm wax column from another manufacturer. I used the Stabilwax because it is a relatively low bleed […]

New Custom UCMR4 Standards for EPA Method 541

We recently stocked custom EPA Method 541 standards made specifically for labs participating in Unregulated Contaminant Monitoring Rule 4 (UCMR4). Quantitative Certificates of Analysis with Data Packs are available for each item. Email csreps@restek.com or phone 800-356-1688 ext. 3 to place your order (items are not available at Restek.com).   Cat# 572263 – Method 541 UCMR4 Standard […]

New Custom UCMR4 Standard for EPA Method 530 on the Rtx-1701

We recently stocked custom EPA Method 530 standards made specifically for labs participating in Unregulated Contaminant Monitoring Rule 4 (UCMR4). Quantitative Certificates of Analysis with Data Packs are available for each item. Email csreps@restek.com or phone 800-356-1688 ext. 3 to place your order (items are not available at Restek.com). Cat# 572262 – Method 530 UCMR4 Standard (in […]

New Custom UCMR4 Standard for EPA Method 525.3

We recently stocked a custom EPA Method 525.3 standard made specifically for labs participating in Unregulated Contaminant Monitoring Rule 4 (UCMR4). Quantitative Certificates of Analysis with Data Packs are available for each item. Email csreps@restek.com or phone 800-356-1688 ext. 3 to place your order (items are not available at Restek.com) Cat# 572261 – Method 525.3 UCMR4 […]

Quadrupole Scan Speed and the 8270 Instrument Checkout Mix – Part II – The DFTPP Evaluation

Yesterday’s blog gave an overview of how choosing the wrong scan speed could be detrimental to the tailing factor evaluation. Before someone asks, I thought we’d spend today looking at the impact of scan speed on the decafluorotriphenylphosphine (DFTPP) tune evaluation. I know I’ve covered this before, but here are the tuning criteria from EPA […]

Quadrupole Scan Speed and the 8270 Instrument Checkout Mix

In my last blog (here), I promised an update on the impact of the detector scan speed on the tailing factor. I had speculated that a pentachlorophenol tailing factor value of 0.94 was more likely < 1.0 because of the scan rate, rather than column overload. The examples I put forward here were collected on […]

An introduction to the benefits of using split injection when performing semivolatiles analysis by 8270D – the instrument checkout mix

This blog is part of a series; the previous installments can be found here and here. We have mentioned several times that the reduced residence time resulting from the fast sample transfer that occurs during a split injection reduces in-inlet degradation and adsorptive loss. Proof of this can be seen in the first run of […]