Application of filter in flame photometry detection
Flame photometric detector is a type of gas chromatography detector, also known as sulfur or phosphorus detector, which has high selectivity and sensitivity for phosphorus and sulfur compounds, and is widely used for the determination of organic phosphorus and organic sulfur pesticide residues; It can also detect thiols in essential oils COS、H2S、CS2、SO2； Thiols in water pollution; H2S, SO2, CS2 in the air; Gas containing sulfides in natural gas.
The commonly used flame photometric detector is a single flame, mainly including hydrogen flame and photometric measurement. Hydrogen flames are similar to flame ionization detectors. The optical measurement system includes a filter, a quartz window, and a photomultiplier tube. The function of a quartz window is to protect the filter from the erosion of combustion products and water gas.
Working principle: When sulfur-containing or phosphorus containing compounds enter the detector from the chromatographic column and burn in a hydrogen rich flame, they will produce chemiluminescent substances and emit characteristic wavelengths of light. Recording these characteristic spectra can detect sulfur and phosphorus.
When S2 molecule is excited to return to the ground state, it emits characteristic spectra (blue and purple) ranging from 350nm to 430nm, corresponding to a maximum intensity wavelength of 393nm. Phosphorus compounds produce phosphorus oxides during combustion, which are reduced from hydrogen to chemiluminescent HPO fragments in a hydrogen rich flame. When the HPO fragment returns to the ground state, it emits characteristic green light (wavelength 480-560nm, maximum intensity corresponding to wavelength 526nm). The filter of flame photometric detector is usually divided into sulfur type and phosphorus type, and the intensity of these two characteristic lights is proportional to the content of the measured component, which is the quantitative basis of FPD. With the development of technology, there are already dual bandpass filters that can simultaneously measure sulfur and phosphorus, eliminating the need for frequent filter replacement. Our company has the ability to produce this type of filter with accurate wavelength positioning.
The biggest development of flame photometric detectors in recent years is the invention of pulse flame photometric detectors (PFPD) and their widespread application. PFPD outperforms FPD in both sensitivity and gas consumption. The pulse flame photometric detector has high sensitivity and selectivity for S, P, and N compounds, and can be used for the detection of more than 20 other elements.
The commonly used flame photometric detector is a single flame, mainly including hydrogen flame and photometric measurement. Hydrogen flames are similar to flame ionization detectors. The optical measurement system includes a filter, a quartz window, and a photomultiplier tube. The function of a quartz window is to protect the filter from the erosion of combustion products and water gas.
Working principle: When sulfur-containing or phosphorus containing compounds enter the detector from the chromatographic column and burn in a hydrogen rich flame, they will produce chemiluminescent substances and emit characteristic wavelengths of light. Recording these characteristic spectra can detect sulfur and phosphorus.
When S2 molecule is excited to return to the ground state, it emits characteristic spectra (blue and purple) ranging from 350nm to 430nm, corresponding to a maximum intensity wavelength of 393nm. Phosphorus compounds produce phosphorus oxides during combustion, which are reduced from hydrogen to chemiluminescent HPO fragments in a hydrogen rich flame. When the HPO fragment returns to the ground state, it emits characteristic green light (wavelength 480-560nm, maximum intensity corresponding to wavelength 526nm). The filter of flame photometric detector is usually divided into sulfur type and phosphorus type, and the intensity of these two characteristic lights is proportional to the content of the measured component, which is the quantitative basis of FPD. With the development of technology, there are already dual bandpass filters that can simultaneously measure sulfur and phosphorus, eliminating the need for frequent filter replacement. Our company has the ability to produce this type of filter with accurate wavelength positioning.
The biggest development of flame photometric detectors in recent years is the invention of pulse flame photometric detectors (PFPD) and their widespread application. PFPD outperforms FPD in both sensitivity and gas consumption. The pulse flame photometric detector has high sensitivity and selectivity for S, P, and N compounds, and can be used for the detection of more than 20 other elements.