Sodium flame photometric determination

Berges, D., G. Schmitt et al. (1959). The effects of helenien and vitamin A on the primary sight process. III. A flame photometric determination of the potassium and sodium content of the retina (German). Z. Biol. Ill 220-227. 

Empirical Modeling of the Effects of Interference on the Flame Photometric Determination of Potassium and Sodium in Water... 

In the following text it shall be demonstrated that possible interferences on the flame photometric determination of potassium and sodium in water can be described and eliminated by empirical mathematical modeling. 

The measured results and the standard deviations of the replicates for the flame photometric determinations of potassium and sodium are presented in Tab. 10-5. The following steps of testing and mathematical modeling correspond to the steps described more detailed in Section 3.3. 

Tab. 10-5. Measured results and standard deviations of replicates for the flame photometric determination of potassium and sodium (in pg mLT1)...

The effects of interference on the flame photometric determination of potassium can be described by the discussed model with only a slight error (Fig. 10-1 a). The effects of interference on the flame photometric determination of sodium are greater, as the model equation 10-16 shows. Also in this case the deviations of the calculated sodium concentrations from the true values are relatively small (Fig. 10-1 b). The comparison... 

K4. Kingsley, G. R., and Schaffert, R. R., Micro-flame photometric determination of sodium, potassium, and calcium in serum with organic solvents. J. Biol. Chem. 206, 807-815 (1954). 

Z. Fang, J. M. Harris, J. RdiiCka, and E. H. Hansen, Simultaneous Flame Photometric Determination of Lithium, Sodium, Potassium and Calcium by Flow Injection Analysis with Gradient Scanning Standard Addition. Anal. Chem., 57 (1985) 1457. 

The procedure for the determination of the alkalis (NaaO, K2O, and Li20) is effectively identical for all classes of material in that 0.25 g of sample is decomposed with hydrofluoric acid together with dilute nitric and sulfuric acids in a platinum dish on a sand bath. The residue is dissolved in dilute nitric acid and alkalis determined directly on the solution by flame photometry or flame atomic absorption spectroscopy (FAAS) in emission mode. Cesium and aluminum sulfate buffers are added to aliquots for the flame photometric determination of sodium and potassium. 

Table 11.4 The effects of modification of ashing procedure on the flame photometric determination of sodium in polyethylenes ...

Several instrument manufacturers supply flame photometers designed specifically for the determination of sodium, potassium, lithium, and sometimes calcium in blood serum, urine, and other biological fluids. Single-channel and multichannel (two to four channels) instruments are available for these determinations. In the multichannel instruments, each channel can be used to determine a separate element without an internal standard, or one of the channels can be reserved for an internal standard such as lithium. The ratios of the signals from the other channels to the signal of the lithium channel are then taken to compensate for flame noise and noise from fluctuations in reagent flow rate. Flame photometers such as these have been coupled with flow injection systems to automate the sample-introduction process (see Section 33B-3). Typical precisions for flow-injection-analysis-based flame photometric determinations of lithium, sodium, and potassium in serum are on the order of a few percent or less. Automated flow injection procedures require l/KIO the amount of sample and 1/10 the time of batch procedures. -... 

Table 7.37 - TTie Effects of Modification of Ashing Procedure on the Flame Photometric Determination of Sodium (sodium ppm)... 

Each sample was fortified with chlorpyrifos, as a reference standard, to determine the recovery during each extraction. Three portions of solvent were used, and the combined extract for each sample was dried with sodium sulfate. Analyses employed gas chromatography/flame photometric detection. Limits of detection for vegetation and animal tissues were 0.2 and 0.007 pg respectively. Recoveries from fortified samples were 82%. Diazoxon occurrence was infrequenf and at trace concentrations. 

Andreae [324,325] has described a gas chromatographic method for the determination of nanogram quantities of dimethyl sulfoxide in natural waters, seawater, and phytoplankton culture waters. The method uses chemical reduction with sodium borohydride to dimethyl sulfide, which is then determined gas-chromatographically using a flame photometric detector. 

The results obtained with ISEs have been compared several times with those of other methods. When the determination of calcium using the Orion SS-20 analyser was tested, it was found that the results in heparinized whole blood and serum were sufficiently precise and subject to negligible interference from K and Mg ([82]), but that it is necessary to correct for the sodium error, as the ionic strength is adjusted with a sodium salt [82], and that a systematic error appears in the presence of colloids and cells due to complexa-tion and variations in the liquid-junction potential [76]. Determination of sodium and potassium with ISEs is comparable with flame photometric estimation [39, 113, 116] or is even more precise [165], but the values obtained with ISEs in serum are somewhat higher than those from flame photometry and most others methods [3, 25, 27, 113, 116]. This phenomenon is called pseudohyponatremia. It is caused by the fact that the samples are not diluted in ISE measurement, whereas in other methods dilution occurs before and during the measurement. On dilution, part of the water in serum is replaced by lipids and partially soluble serum proteins in samples with abnormally increased level of lipids and/or proteins. 

More recent flame photometric methods rely on direct measurement of the phosphorus emission. If organophosphorus compounds are injected into a hydrogen flame, a continuous emission is obtained in the 490-650 nm region. A broad band system, with an intensity maximum at 526 nm, is superimposed on this background139 it is attributed to the HPO species formed in the flame. An early determination of phosphorus at 0.01-0.04 m concentrations was based on examination of the continuous emission standard and sample solutions were injected into the burner and the intensities were measured at 540 nm the calibration graph was linear down to the detection limit of 10 4 M phosphorus sodium or calcium, if present in the sample, interfered with the results140. 

Potassium is analyzed in chemicals that are used in the fertilizer industry and in finished fertilizers by flame photometric methods (44) or volumetric sodium tertraphenylboron methods (45) as approved by the AO AC. Gravimetric determination of potassium as IC PtClknown as the Lindo-Gladding method (46), and the wet-digestion determination of potassium (47) have been declared surplus methods by the AO AC. Other methods used for control purposes and special analyses include atomic absorption spectrophotometry, inductively coupled plasma (icp) emission spectrophotometry, and a radiometric method based on measuring the radioactivity of the minute amount of the isotope present in all potassium compounds (48). 

Finally, the flame photometric methods for determination of sodium and potassium have been adapted to the device. In this case, after the addition of lithium as internal standard, the electrolytes are dialyzed into the recipient stream, which is then pumped into an atomizer-burner of more or less conventional design. A colorimeter has been designed to allow for simultaneous recording of sodium and potassium, utilizing a two-channel recorder as optional equipment. This arrangement would tend to conserve sample. Without the dual recorder, the recorder supplied as part of the basic instrument is used, and the specimens are sampled once for sodium and once for potassium. 

Matthias et al. [216] have described a comprehensive method for the determination of aquatic butyltin and butylmethyltin species at ultratrace levels using simultaneous sodium borohydride hydridisation, extraction with gas chromatography-flame photometric detection and gas chromatography-mass spectrometric detection. The detection limits for a lOOmL sample were 7ng L 1 of tin for tetrabutyltin and tributyltin, 3ng L 1 of tin for dibutyltin and 22ng L 1 tin for monobutyltin. For 800mL samples detection limits were l-2ng L 1 tin for tri- and tetrabutyltin and below lng L 1 tin for dibutyltin. The technique was applied to the detection of biodegradation products of tributyltin in non saline waters. 

Singh and Lapointe [485] analysed six organophosphates with a P=S group after oxidation with a neutralized solution of sodium hypochlorite. The substrates were thus converted into oxo compounds and, with the aid of a flame photometric detector sensitive to phosphorus, were determined in vegatables at levels of tenths of 1 ppm. 

NH4 exchanged forms were prepared by multiple treatment of the original sodium formed by 0.5 N aqueous solution of NH4CI at about 90 °C accompanied by washing to remove the chloride ions. Samples were dried at 120 °C and calcined at 540 °C for 4 h in air. The sodium amount and degree of exchange in different H "- forms were determined by flame photometric analysis. 

Janssen (Jl) suggested that spectral analysis, until then used only for qualitative observations, was suitable also for quantitative work. He felt that such a development would be particularly advantageous in the case of elements like sodium which were difficult to determine by classic procedures. His suggestions bore fruit 3 years later when Champion et al. (Cl) constructed an instrument for the determination of sodium in plant ash. A solution of plant ash was introduced into the flame by means of a platinum wire and the emission intensity measured by comparing it by means of a visual photometric attachment with light from a reference constant-intensity sodium flame. This spectronatrometre was the first flame photometer and when one considers that it was capable of an accuracy of between 2 and 5 %, it is interesting that it was not for more than 70 years that the method was applied to clinical problems. 

Sulfur dioxide may be determined after removing it from foods by distillation, and titration with sodium hydroxide in the presence of methyl red. GC headspace analysis with a flame photometric detector has also been used for the quantification of this food additive. 

Among atomic emission spectrometry (AES) methods, the classic flame photometric technique is still favored for determination of sodium and potassium in foods. 

The first detector to be used for SFA was a photometer, and photometric determinations still form the vast majority of current methods. Other detectors in common use are UV spectrophotometers, used primarily for pharmaceutical compovmds and for bitterness in beer flame photometers, for potassium and sodium determination fluorimeters, used primarily for measuring low levels of determinants in the presence of interferences, such as the determination of histamine in blood, and vitamins in food extracts and ion-selective electrode and pH detectors. In principle, almost any detector with flow-through capability can be used with SFA systems, and determinations based on densitometry, thermometry, and luminescence have been published, among others. 

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