Detectors photometric detector

MSFIA-CE system applied to the preconcentration, separation, and determination of nitrophenols. Detector photometric detector cell HC holding coil IV injection valve RC reaction coil SV selection valve V solenoid valve. 

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. 

For an analyte of molecular weight 5000 and good chromatographic conditions, most photometric detectors can be expected to provide detection limits of 2—5 ng. Improvement into the mid-picogram or lower range normally requires the use of more sensitive detection means such as fluorescence or electrochemical detectors. 

The flame-photometric detector (FPD) is selective for organic compounds containing phosphoms and sulfur, detecting chemiluminescent species formed ia a flame from these materials. The chemiluminescence is detected through a filter by a photomultipher. The photometric response is linear ia concentration for phosphoms, but it is second order ia concentration for sulfur. The minimum detectable level for phosphoms is about 10 g/s for sulfur it is about 5 x 10 g/s. 

The comparison of analytical characteristics HPLC methods of determination of phenols with application amperometric and photometric detectors was caiiy out in this work. Experiment was executed with use liquid chromatograph Zvet-Yauza and 100 mm-3mm 150mm-3mm column with Silasorb C18 (5 10 p.m). With amperometric detector phenols were detected in oxidizing regime on glass-cai bon electrodes. With photometric detector phenols were detected at 254 nm. 

Application developed by using a Fisons GC 8000 chi omatogi aph where the two columns were installed and coupled via a moving capillary stream switching (MCSS) system. The chi omatogi aph was equiped with a flame-ionization detector on the MCSS system outlet and a Flame-photometric detector on the main column outlet, and a split/splitless injector. 

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. 

EC = electrical conductivity detector ECD = electron capture detector FPD = flame photometric detector GC = gas chromatography HPLC = high performance liquid chromatography NPD = nitrogen phosphorus detector TID = thermionic detector UV = ultraviolet spectroscopy... 

Kumata H, H Takada, N Ogura (1996) Determination of 2-4-morpholinyl benzothiazole in environmental samples by a gas chromatograph equipped with a flame photometric detector. Anal Chem 68 1976-1981. 

GC nitrogen-phosphorus detector (NPD), flame photometric detector (FPD), electron capture detector (BCD), flame ionization detector (FID), mass-spectrometric detector (MS)... 

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. 

Flame photometric detector fitted with a 394-nm sulfur-specific filter 240 °C... 

Ethylenethiourea (ETU) is a toxic decomposition product/metabolite of alky-lenebis(dithiocarbamates). This compound could be generated during processing of treated crops at elevated temperature. Different chromatographic methods to determine the residue levels of ETU have been published. After extraction with methanol, clean-up on a Gas-Chrom S/alumina column and derivatization (alkylation) with bro-mobutane, ETU residues can be determined by GC with a flame photometric detector in the sulfur mode. Alternatively, ETU residues can also be determined by an HPLC method with UV detection at 240 nm or by liquid chromatography/mass spectrometry (LC/MS) or liquid chromatography/tandem mass spectrometry (LC/MS/MS) (molecular ion m/z 103). ... 

Gas chromatograph for fused-silica capillary or packed columns, equipped with a flame photometric detector (with sulfur filter), Hewlett-Packard, Carlo Erba, or equivalent... 

In the case of crop residues, GC determination is carried out on the hydrolyzed product, i.e., methomyl oxime, instead of alanycarb to make effective use of its substantially higher response to the flame photometric detector. In order to prevent vaporization loss of methomyl oxime, ethylene glycol must be added prior to concentration in Section 6.3. In all other concentration operations, full account must also be taken of the high volatility of both alanycarb and methomyl oxime, especially in the process of removal of the last traces of solvents. Alanycarb residue in the sample is stable under storage condition at -20 °C for at least 100 days. 

Figure 3.14 Dual-flane photometric detector (Varian). A, Schematic diagram of the dual-flame burner B, Schematic diagram showing the relationship between the burner and the photometric viewing components. (Reproduced with permission from ref. 177. Copyright American Chemical Society).

Figure 3 Least squares calibration line for photometric detector. (From Dorschel, C. A., Ekmanis, J. L., Oberholtzer, J. E., Warren, Jr., F. V., and Bidlingmeyer, B. A., LC detectors evaluations and practical implications of linearity, Anal. Chem., 61, 951 A, 1989. Copyright American Chemical Society Publishers. With permission.)...

FPD Flame photometric detector HC(L) Hollow cathode (lamp)... 

Gas chromatography with a flame photometric detector (Sass and Parker 1980) and multiphoton ionization mass spectrometry (MI/MS) (Syage et al. 1988) have also been used to analyze diisopropyl methylphosphonate in air samples. 

---