Flame photometric detector phosphorus-selective

Flame photometric detector (FPD) selective to compounds containing sulfur and phosphorus... 

Other Detectors Two additional detectors are similar in design to a flame ionization detector. In the flame photometric detector optical emission from phosphorus and sulfur provides a detector selective for compounds containing these elements. The thermionic detector responds to compounds containing nitrogen or phosphorus. 

Flame Photometric Detector3 With the flame photometric detector (FPD), as with the FID, the sample effluent is burned in a hydrogen/air flame. By using optical filters to select wavelengths specific to sulfur and phosphorus and a photomultiplier tube, sulfur or phosphorus compounds can be selectively detected. 

On the other hand, if only specific GC detectors, e.g. the electron capture, nitrogen-phosphorus or flame photometric detectors, are tested, the argument of lack of GC method sensitivity is not acceptable. In most cases mass spectrometric detectors provide the sensitivity and selectivity needed. Unfortunately, tandem mass spectrometry (MS/MS) or MS" detectors for GC are still not widely used in official laboratories, and therefore these techniques are not always accepted for enforcement methods. 

The responses of these three detectors to a variety of organophosphorus molecules have often been compared the results seem to vary from compound to compound165,179,217,238,289. In many instruments the stream is split and passes through several detectors for parallel measurements184,187,298. The flame photometric detectors are the most selective for phosphorus, yield less extraneous peaks and make the identification work easier188. 

A flame photometric detector measures optical emission from phosphorus, sulfur, lead, tin, or other selected elements. When eluate passes through a Hrair flame, as in the flame ionization detector, excited atoms emit characteristic light. Phosphorus emission at 536 nm or sulfur emission at 394 nm can be isolated by a narrow-band interference filter and detected with a photomultiplier tube. 

Organochlorine pesticides and OPPs have been determined mainly using GC, because of the stability and volatility that most of them show under chromatographic conditions and, particularly, the availability of element-selective detectors that display high selectivity for OCPs (electron-capture detector, ECD), and OPPs (flame photometric detector, FPD, and nitrogen phosphorus detector, NPD). Mass spectrometry-based detection is also more popular in GC than in HPLC (1,2,12,16). 

Selective to sulfur and phosphorus compounds more selective than NPD to compounds containing phosphorus Flame photometric detector Organophosphorus pesticides (EPA 8141) Sulfur compounds may interfere with organophosphorus pesticides. 

Most OP insecticides may be determined directly by GC using the phosphorus-selective flame photometric detector (FPD) which helps to minimize clean-up. However, it must be emphasised that the FPD is only a "selective" detector for phosphorus (at 540 nm) or sulphur (at 394 nm) and not an "element specific detector". 

Some techniques may offer selective screening as well as specificity —e.g., microcoulometric methods described by Coulson et al. (24). This technique consists of a combination of gas chromatography, combustion, and continuous coulometric titration for chlorine or sulfur. The development of the flame photometric detector offers a similar potential for the selective screening and specificity of pesticides which contain phosphorus or sulfur (25). Even so, one or more tests in addition to the initial... 

Traditionally, gas chromatography (GC) was the preferred approach for the analysis of pollutants in water, due to the high sensitivity and selectivity achieved, thanks to its selective detectors such as the nitrogen-phosphorus (NPD), the flame photometric detector (FPD), and electron-capture detector (ECD), and to the ease of coupling to mass spectrometry (MS). However, high-performance liquid chromatography (HPLC or LC) is the most powerful approach for the determination of polar, nonvolatile, and thermolabile compounds (i.e., those which are not GC amenable). 

Gas chromatography with either sulfur chemiluminescence detection or atomic emission detection has been used for sulfur-selective detection. Selective sulfur and nitrogen gas chromatographic detectors, exemplified by the flame photometric detector (FPD) and the nitrogen-phosphorus detector (NPD), have been available for many years. However, these detectors have limited selectivity for the element over carbon, exhibit nonuniform response, and have other problems that limit their usefulness. 

Flame photometric detector (FPD) is a representative of optical detectors for gas chromatography. In FPD, column effluent is introduced to a hydrogen flame, which breaks analyte molecules into atoms. The temperature of the flame is sufficient to excite some atoms, especially sulphur and phosphorus. These excited atoms emit characteristic lights on return to the ground state. The light emitted by the element of interest is selected by a suitable bandpass filter and measured... 

In the early 1990s Amirav et al. introduced a new strategy for the operation of FPD based on a pulsed flame instead of a continuous flame for the generation of flame chemiluminescence. This pulsed flame photometric detector (PFPD) is characterized by the additional dimension of a light emission time and the ability to separate in time the emission of sulfur species from those of carbon and phosphorus, resulting in considerable enhancement of detection selectivity. In addition, detection sensitivity is markedly improved, thanks to ... 

The flame photometric detector (FPD) is selective to sulphur- or phosphorus-containing compounds and it has been used in the determination of organophosphorus FRs. In FPD, the emitter for phosphorus compounds in the flame is excited HPO (Xj ax = doublet 510 to 526 nm) and detection requires a suitable interference filter for isolation of the emission band. For organophosphorus FRs, a phosphorus filter at 526 nm has been used in the detection. The detection limits for the organophosphates have been on the ng level. 

The response of the flame photometric detector is due to chemiluminescence subsequent to combustion of certain organic molecules in an energetic flame. The initial work on this principle by Brody and Chaney [109] was primarily concerned with selective detection of sulfur and phosphorus compounds, although detection of other elements is also feasible with different optical filters. 

Flame photometric detector FPD, a selective GC detector for sulphur and phosphorus containing compounds. Separated components pass into a hydrogen-rich flame where they undergo a series of reactions to produce excited species HPO and S2. The resulting atomic emission spectrum is monitored using narrow band pass filters (526 and 394 nm, respectively) and a photomultiplier detector, sensitivity is 10 to 10 " gs . ... 

Element selective detectors Element selective detectors applicable in pesticide residue analysis include electron capture detector (ECD), electrolytic conductivity detector (ELCD), halogen-specific detector (XSD), nitrogen phosphorus detector (NPD), flame photometric detector (FPD), pulsed flame photometric detector (PEPD), sulfur chemiluminescence detector (SCD), and atomic emission detector (AED). To cover a wider range of pesticide residues, a halogen-selective detector (ECD, ELCD, XSD) in conjvmction with a phosphorus- (NPD, FPD), nitrogen- (NPD), and/or sulfur-selective detector (FPD, SCD) is commonly used. A practical approach is to spht the column flow to two detectors that reduces the number of injections however, the reduced amoimt of analyte that reaches the detector must be considered. 

Selective GC detectors aid in the detection and identification of compounds containing specific elements halogens with electron capture detector (BCD) or electrolytic conductivity detector (ELCD) nitrogen and phosjAorus with nitrogen-phosphorus detector (NPD) sulfur and phosphorus with flame photometric detector (FPD) and sulfur with sulfur chemiluminescence detector (SCD). The development of the atomic... 

The flame photometric detector (FPD) has been widely applied to the analysis of air and water pollutants, pesticides, and coal hydrogenation products. It is a selective detector that is primarily responsive to compounds containing sulfur and phosphorus. In this detector, the eluent is passed into a low-temperature hydrogen-air flame, which converts part of the phosphorus to an HPO species that emits bands of radiation centered at about 510 and 526 nm. Sulfur in the... 

CWA alarm when a flame photometric detector is used for detection. This is because flame photometric detectors are made specifically to respond to chemicals containing phosphorus and sulfur. Detectors are always subject to yielding false positive alarms since no detector can be made 100% selective to only targeted chemicals. Most detection devices are made to detect multiple compounds. Therefore, a different technique may be necessary to serve as a backup to confirm alarms to reduce the potential for false positive alarms. 

When using selective detectors, one must consider the possible change in the response factor for a particular component due to the presence of the background matrix. For example, a selective detector for sulfur and phosphorus-containing compounds is the flame photometric detector, but it shows a diminished response... 

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