Urgent inquiry regarding the detection limit of FID gas chromatography, waiting online

Three questions: 1. Has the sample entered the chromatography column?； 2. Whether the chromatography column can achieve separation ； 3. Whether the detector can detect it. Solution 1: Check for air leaks in the system, especially at the injection port. Verify that the chromatography column is installed correctly, and pay attention to whether the length of the injection port is appropriate (it seems that 4–6 mm of graphite gasket should protrude; the exact details can be found in the instrument’s manual) ； 2. Check whether the chromatography column is contaminated; it is possible to age the column, and if necessary, reduce the length at the inlet by about 0.5–1 m ； 3. Clean the detector nozzles

It seems like the replies from above were generated by AI or are the responses of amateurs. The FID detector has high sensitivity to hydrocarbons, as it is based on the large number of hydrocarbon fragments formed. However, when the sample or the component being analyzed contains atoms with high electronegativity, the electrons in these fragments are strongly bound by those atoms, resulting in a significant decrease in detection sensitivity. It is recommended to use an electron capture detector, namely ESD, as this type of detector has high sensitivity to halogenated hydrocarbons with high electronegativity. The reply from upstairs didn’t address the issue at all.

The time spent on analysis isn’t very long – about twenty years. The theoretical foundation isn’t very strong, but there are many practical problems to solve

This post was last edited by qqgd on 2025-4-2 20:40. What I’m talking about is not theory at all, but rather the actual configuration of chromatography systems. There are only a few commonly used detectors in chromatography; components with certain properties require detectors that suit those properties – it’s simply a matter of configuring gas chromatography systems appropriately. This is a practical question – in which aspect do you demonstrate 20 years of work experience? Providing appropriate explanations and solutions to practical problems is the true manifestation of integrating experience with theory in practice. The poster’s question concerns sensitivity; is there any significant connection with the separation capability of the chromatography column and the performance of the detector? The original poster can’t even understand the questions properly; it must have been really tough working for these twenty years. If the poster has a certain number of samples for detecting such fluorocarbons as part of their regular analysis tasks, it is advisable to install an ESD detector; such a detector costs around ten thousand yuan or so, but it is much more cost-effective than sending the samples out for testing elsewhere. Also, pay attention to maintaining the purity of the carrier gas; it is advisable to install a dedicated ESD carrier gas purification device.

This is my last reply to you! Different opinions can be expressed; we should not belittle others. We just need to focus on the outcome of solving the problem. What I’m referring to is the way in which front-line analysts approach problem-solving. We produce more than a dozen products that contain halogens, and the instruments we use include the Lunan Ruihong 6890 made in China, as well as Agilent models 7820, 8860, and 8890. I have encountered situations where there were issues related to reduced detection accuracy on more than one occasion, and I was the one who resolved those problems.

This post was last edited by qqgd on 2025-4-3 08:54. Take a look at your own replies to see which ones provide effective responses to the original poster’s question. Is the original poster’s question not clear? Rather than saying you’ve been working in analysis for 20 years, it’s more accurate to say you’ve just been wasting time over those 20 years; you can’t even address basic chromatography analysis issues straightforwardly, and yet you still have the audacity to be dissatisfied with others’ corrections. Many of the questions posed by this poster are very specific; it’s unacceptable not to provide explanations and solutions to such specific issues. Pointing out that your responses are off-topic is a form of respect toward you. With an attitude like yours, you’d better not show up in public in the end. Do you understand the principle that those who are not myself but who deserve it are my teachers? If one doesn’t even have the basic ability to discuss issues or the necessary level of understanding at one’s workplace, then there’s no point talking about having worked there for over 20 years – it would only be a source of ridicule. Just listing a few chromatography models is enough to show that you’re knowledgeable with 20 years of work experience? That only makes it seem like looking at the world through a narrow perspective.

I didn’t force anyone to accept my reply; I merely offered my suggestions. This is a place for discussing issues, not a place for attacking others. Did I happen to step on your tail as well?

This post was last edited by qqgd on 2025-4-4 at 18:06. Since you used vulgar language in your reply, I won’t hold back in wishing your mother and all the female members of your family good health and the absence of sexually transmitted diseases.

Go home and take care of your mother and daughter; you don’t need to worry about your wife, after all you don’t mind that little color difference