Phosphorus emission from

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. 

White Phosphorus Oxidation. Emission of green light from the oxidation of elemental white phosphoms in moist air is one of the oldest recorded examples of chemiluminescence. Although the chemiluminescence is normally observed from sotid phosphoms, the reaction actually occurs primarily just above the surface with gas-phase phosphoms vapor. The reaction mechanism is not known, but careful spectral analyses of the reaction with water and deuterium oxide vapors indicate that the primary emitting species in the visible spectmm are excited states of (PO)2 and HPO or DPO. Ultraviolet emission from excited PO is also detected (196). 

This method is used for the determination of total chromium (Cr), cadmium (Cd), arsenic (As), nickel (Ni), manganese (Mn), beiylhum (Be), copper (Cu), zinc (Zn), lead (Pb), selenium (Se), phosphorus (P), thalhum (Tl), silver (Ag), antimony (Sb), barium (Ba), and mer-cuiy (Hg) stack emissions from stationaiy sources. This method may also be used for the determination of particulate emissions fohowing the procedures and precautions described. However, modifications to the sample recoveiy and analysis procedures described in the method for the purpose of determining particulate emissions may potentially impacl the front-half mercury determination. 

Fujiwara et al. [94] found that, when present as a heteropolyacid complex, molybdenum(VI), germanium(IV), and silicon(IV) produced CL emission from the oxidation of luminol, and similar CL oxidation of luminol was observed for arsenic(V) and phosphorus(V) but with the addition of the metavanadate ion to the acid solution of molybdate. A hyphenated method was therefore proposed for the sensitive determination of arsenate, germanate, phosphate, and silicate, after separation by ion chromatography. The minimum detectable concentrations of arsenic(V), germanium(IV), phosphate, and silicon(IV) were 10, 50, 1, and 10... 

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. 

This series of studies of the variation of the Phosphorus Emission Index generated from several applications of the special Noack instrument has been effective in revealing some of the characteristics of the phosphorus volatilization from ZDDPs made from a primary and a secondary alcohol. Thus, the primary objective of this study has been met. That is, it has been shown that phosphorus volatilization and the associated PEI are affected strongly by the chemistry of the ZDDP. Whether or not these differences are caused by thermodynamic effects and/or some form of steric interference remains to be determined, as well as the range of differences that may exist among the different alcohols. 

Selby, T. W., Phosphorus Volatility of Lubricants — Use of the Phosphorus Emission Index of Engine Oils, 9th F L Asia Conference, Singapore, January 21—24, 2003. (available on CD from F L Asia, Inc., Manila, Philippines). 

The role of organic phosphorus in N -fixation and greenhouse gas emissions from the oceans was demonstrated by Sanudo-Wilhelmy et al. (2001). Many studies have reported that N -fixation is limited principally by the availability of iron (e.g. Falkowski, 1997), an essential coprotein for nitrogenase (Atlas and Bartha, 1993). However, Sanudo-Wilhelmy et al. (2001) recently reported that rates of N -fixation were highly correlated with the phosphorus content of a cyanobacterial colony rather than iron availability or intracellular iron content. The study of Sanudo-Wilhelmy et al. (2001) provides further evidence of the coupling of the phosphorus cycle with the carbon and nitrogen cycles. Indeed, each of... 

The technique of representing the intensities of spectral lines as a function of time is referred to as time-resolved spectroscopy. Time resolution of spectroscopic information has been applied to many problems, such as the kinetics of fast decay phosphorus, radiation from fast photolysis sources, and exploding wire phenomena. Of most importance to analytical spectroscopy is the use of time-resolved spectroscopy to study the characteristics of ac spark and ac arc discharges of the type normally used for analytical emission spectral analysis, since such information may be useful in optimizing operating conditions. 

Beta particles are electrons emitted with very high energy from many radioisotopes. Positively charged counterparts of beta particles are called positrons. Positronic and electron emissions from radioactive atoms can be shielded by thin metal foils or one-quarter inch of plastic. Tritium ( H), phosphorus-32, and carbon-14... 

---