HS Sample Loop Issue (cGMP)

[slickproof]

Empower 3 does not have the option for a 2 mL sample loop configuration for the Agilent 7697A Headspace Sampler. All the procedures my lab uses for analysis utilize a 2 mL loop. These tests are conducted in a GMP environment.

I ran a couple repeatability tests (6 injections of 1 standard) using a 2 mL loop physically installed. One used the 1 mL loop configuration in Empower 3 and the other used the 3 mL loop configuration. Peak area results were comparable to each other with an RSD of 2-3% for each run. Our requirement is < 5%.

I determined that the mismatch in physical loop size and loop configuration in Empower only affected precision. Am I correct in this determination? Are there any other factors that I am missing that can affect the analyses?

Any help is greatly appreciated!!

[HippyLabRat]

Is the option by drop down or radio button?

[Peter Apps]

Empower 3 does not have the option for a 2 mL sample loop configuration for the Agilent 7697A Headspace Sampler. All the procedures my lab uses for analysis utilize a 2 mL loop. These tests are conducted in a GMP environment.

I ran a couple repeatability tests (6 injections of 1 standard) using a 2 mL loop physically installed. One used the 1 mL loop configuration in Empower 3 and the other used the 3 mL loop configuration. Peak area results were comparable to each other with an RSD of 2-3% for each run. Our requirement is < 5%.

I determined that the mismatch in physical loop size and loop configuration in Empower only affected precision. Am I correct in this determination? Are there any other factors that I am missing that can affect the analyses?

Any help is greatly appreciated!!

Welcome to the forum.

Your measured repeatability and found that it was the same for the two settings of the loop size in Empower. Therefore you have shown that the settings in Empower do not affect precision. If the loop volume settings are used to calculate results they will have very serious effects on accuracy though.

And when you are talking about measurement results "comparable" does not mean "similar", it means capable of comparison.

Peter

[slickproof]

The selection is made via a drop down menu.

The peak areas of both repeatability injection sequences were in total 3.5% RSD (all 12 injections together). Typical %RSD for 6 standard injections is < 1% RSD.

For clarity, peak areas between both injections sets were between 350-370 pA.

[Peter Apps]

The selection is made via a drop down menu.

The peak areas of both repeatability injection sequences were in total 3.5% RSD (all 12 injections together). Typical %RSD for 6 standard injections is < 1% RSD.

For clarity, peak areas between both injections sets were between 350-370 pA.

What is the mean and rsd of the two sets of 6; one with the 1 ml setting and one with the 3 ml setting ? And are they different ?

If you change the loop size setting in Empower does it automatically change any of the other operating conditions such as vial pressure or loop fill time ?

Peter