I want to do a GC- MS analysis for Prodigiosin pigment extracted from Serratia. It's boiling point is 554.3 Celcius. Should I use headspace method?

How do I estimate the phase distribution of a dilute solute using vapor pressure?

What is the most fundamentally accurate way to calculate the distribution of a solid between the condensed, vapor, and/or liquid phases? Let's say I have a very small amount of elemental silver,...

22 December 2020 8,060 0 View

Why are there broad, irregularly-shaped peaks that elute early in my gas chromatogram ?

We just replaced our GC-FID with a new column and conditioned the column before using it. When I started my running blanks and samples using a specific temperature program, there always appears...

13 November 2019 9,378 3 View

How to avoid protease degradation?

We purified a 50 KDa metalloprotease (Serralysin) from Serratia marcescens. We employed a DEAE cellulose in tris buffer and recovery it in a elution with 100 mM NaCl in the same tris buffer (20 mM...

10 November 2019 1,929 11 View

What is ideal volume for head-space in the semi-continuous anaerobic digestion? Is 30% of Total Volume of the reactor recommended?

I am currently formulating a farm model for AD of a highly biodegradable substrate of maximum biogas yield of about 485 mL biogas/gVS. I want to include a percentage to account for the headspace...

10 November 2019 8,081 1 View

What is ideal volume for head-space in the semi-continuous anaerobic digestion? Is 30% of Total Volume of the reactor recommended?

I am currently formulating a farm model for AD of a highly biodegradable substrate of maximum biogas yield of about 485 mL biogas/gVS. I want to include a percentage to account for the headspace...

31 October 2019 4,792 7 View

How to spike solid food samples for the HS SPME-GC-FID analysis of volatiles?

I am extracting very volatile compounds from solid foods using Headspace Solid Phase Microextraction then analyse the extracts using GC-FID. So currently I'm trying to develop a method but...

08 August 2019 9,056 7 View

How to perform GC manual headspace sampling?

Hi everyone. May I know is there an established method for GC-FID headspace sampling? I did triplicates for the same concentration of analyte via manual sampling technique (using a air-tight gas...

17 July 2019 3,428 3 View

Antimicrobial compound produced during lag phase?

I have been studying two unknown soil isolates (one suspected to be Pseudomonas fluorescens) as part of my experimental project. They are both producing some antimicrobial compound in lag/early...

31 December 2018 2,391 1 View

What is the name of the media specifically used for bacteria performing casein hydrolysis?

We want to check if insects have a Serratia marcescens infection. Hence we wanted to know about Serratia marcescens selective medias.

10 November 2018 4,563 3 View

Can anyone give me a simple extraction mode for date fruit volatile compounds, end/or the adequate GCMS protocol analysis (without SPME, headspace!) ?

Hello All, we are analyzing the volatile product of fresh dates, and I want to know what type of extraction / solvents (soxhlet, cold, ...,), and their analysis protocol by the GCMS, knowing we do...

07 August 2018 4,157 4 View