Water sample preservation LC-MS?

Cathrine Brecke Gundersen @Cathrine-Gundersen

17 December 2019 0 7K Report

What are the generally recommended water sample preservation techniques for direct injection in LC-MS? To avoid biodegradation of the analyte. I know this will depend on the method used, but I am wondering if you can share your experiences or knowledge on the most commonly used type of preservation.

- NaN3, HgCl2, sulfuric acid/nitric acid addition to pH < 2?

Badges
Science topic

Similar topics
Computer Science
Program

More Cathrine Brecke Gundersen's questions See All

Should the PARAFAC model be validated using normalised or non-normalised data?

With a sample set ranging in DOC values, normalization is necessary. However, the PARAFAC model using normalization has poorer split-half analysis results and stranger looking emission and...

14 August 2023 4,764 0 View

Suggestions for dyes to monitor bacterial growth kinetics?

I am planning to run an experiment that requires me to monitor growth kinetics in aerobic bacterial communities over approximately 7 days. The communities should have between 30-100 species...

17 June 2020 4,546 1 View

Meta-analysis question: CanHazard Ratios (HRs) be aggregated with other HRs and/or other effect sizes?

Hello there, I am a Ph.D student in forensic psychology. I am currently about to conduct a systematic review and meta-analysis. For the meta-analysis, many eligible studies reported Hazard Ratios...

01 June 2020 4,006 1 View

Multiple samples on EcoPlate from Biolog?

Does anyone have experience with using the EcoPlates from Biolog to run 3 different samples instead of three replicates of 1 sample? I want to use the data to characterize the niche space and...

30 September 2019 4,005 4 View

Is there difference between total standing voltage and total blocked voltage in inverter?

Is there difference between total standing voltage and total, blocked voltage in inverter? or both are the same term? if both are different how can i calculate each one?

31 July 2019 318 12 View

How to do a paired t-test/Wilcoxon signed rank test over time with multiple replicates per time-point?

Hi, I am a bit unsure about how the data should be preprossessed prior to performing a paired statistical test. Lets say I have two groups A and B where I measure something every day for twenty...

03 June 2019 1,575 4 View

How do I change something to show I published a review, not the original?

I was not given the option to specify I published a review, and am being asked if the author of the work I reviewed is a co-author. I have published over 50 reviews of the work of others.

05 November 2018 345 7 View

Community Development and Dialogue?

I have an assignment about dialogue in community development and was wondering if anyone has some ideas for reference materials. I only have a week before it is due so need the help pretty...

25 August 2017 2,394 5 View

How do I get rid of Endotoxins?

I get endotoxins in my antibodies that are purifed on Protein A column in a chromatography system. The sample are tested before introduced into the system and are negative. I have tried to wash...

22 May 2016 1,668 7 View

Can anyone suggest articles for research on barriers to online study for students/mature age etc.?

Hi, Need them for research subject report. Articles on online study barriers. Thanks

25 August 2014 3,184 10 View

• What the possible Persistent Organic Pollutants and Heavy metals present in fluorspar, sediments, and water bodies around its mining area?

Approximate concentrations are require in compared with the WHO permissible limts

11 August 2024 2,723 1 View

Handling Missing Data and Building a Predictive Model with Incomplete Information ?

I am developing a predictive model for a water supply network that involves 20 influencing points. However, I only have historical data for 10 out of these 20 points. I would like to know how to...

10 August 2024 4,005 2 View

Do interactions between biosphere, carbon cycle, & water cycle impact global warming & interaction between atmosphere & hydrosphere?

How do interactions between the biosphere, the carbon cycle, and the water cycle impact global warming and interaction between the atmosphere and the hydrosphere?

09 August 2024 3,291 2 View

Is it true that $\det(V(A))$ may be only $\pm 1$, depending on $n$, for the last symmetric tridiagonal matrix $A$?

One can try to generalize the Vandermonde determinant in the following direction: Let $A$ be any symmetric $n$-order square matrix. Consider its powers' diagonal elements $(A^k)_{ii}$ and...

08 August 2024 6,690 1 View

Separation of organic acids-HPLC?

Hello What should be done to separate and identify organic acids in HPC when their RetTime is the same?Like oxalic acid with Propanoic Acid.or acids that have a very close RetTime.

07 August 2024 8,782 3 View

RNA later for the preservation of RNA in fecal samples at room temperature for one day (37°C)?

I am planning to collect human fecal samples for metatranscriptomic analysis using MGI. These samples are from indigenous people living in a region with high temperatures. I will have access to a...

06 August 2024 1,367 3 View

The aqueous fraction of the hydroethanolic extract is showing the presence of palmitic acid. What is the mechanism responsible ?

Palmitic acid presence in aqueous fraction

05 August 2024 8,624 4 View

Determining the worth of a point improvement in Hamilton Depression Scale?

Dear readers, Thanks for your attention. I am wondering about the health economic problem of quantifying the value of interventions which a) prevent, b) improve symptom profile and c) ultimately...

05 August 2024 3,246 1 View

Do you have good tips for seaweed tissue preservation in the field for post RNA extraction?

I will be with my students collecting seaweed samples in a marine farm and later we will process this tissue for RNA isolation and further sequencing. Does anyone have tips on how to collect the...

04 August 2024 501 2 View

How to Add Missing Water Molecules in Protein-Membrane Simulations?

I have protein-membrane simulations (PDB, PSF, DCD) and have noticed that water molecules near the protein are not visible in the simulations. How can I fix this issue? Is there a way to place the...

04 August 2024 1,200 2 View