A Y-shaped Teflon connector was designed to branch the capillary of a conventional commercial flame atomic absorption spectrometer for the introduction of inorganic Hg21 aqueous solution and KBH4 solution. The two solutions were merged inside the connector before being nebulized into an aerosol by air in the nebulizer of the instrument, and the atomic absorption of mercury in the cold vapor and the aerosol was directly measured at ambient temperature without gas-liquid separation and without a flame. The limit of detection was 0.01mg/mL-1. The connector is easy to assemble and disassemble. It is a very simple and cost-effective way to exploit a conventional atomic absorption spectrometer for the determination of mercury. This method also features the use of a plentiful auxiliary gas (the ambient air only), simple reagents (KBH4 and NaOH only) and no need for flame or electricity for atomization.

A new photochemical reaction for mercury chemical/cold vapor generation (CVG) coupled to atomicfluorescence spectrometry (AFS) is described for the speciation analysis of inorganic mercury ion (Hg21) andorganic methylmercury (MeHg) in aqueous solution. The new CVG simply uses one reagent, formic acidonly, to react with Hg21 or MeHg in aqueous solution, under room natural light (Vis) or ultravioletirradiation (UV), for the generation of cold mercury vapor, which is subsequently detected by AFS. In thepresence of the UV, both Hg21 and MeHg can be converted to Hg0 for the determination of total mercury;and only Hg21 can be reduced to Hg0 with the Vis, thus determining Hg21 only. Then, the concentration ofMeHg can be calculated by subtracting the Hg21 concentration from the total mercury concentration. Theoptimal conditions for the best CVG efficiency are discussed, together with the interference from transitionmetals. There exists no significant interference from as high as 100 mg L_1 Co21 or Ni21, and 50mg L_1Cu21 for the determination of as low as 5mg L_1 Hg21. The new CVG minimizes the contamination sourcesand avoids off-line pre-oxidation of MeHg. A simple Hg21 standard series can be used for the calibration ofboth Hg21 and MeHg, eliminating the use of more toxic and more expensive MeHg standard series. Thelinear dynamic ranges of the calibration curves are up to 25mg L_1 with the UV and 300mg L_1 with theVis. The limit of detection is 0.003 or 0.2mg L_1 for total mercury with the UV or Hg21 with the Vis,respectively. The accuracy of this method was validated by determination of mercury in one certifiedreference water sample. The new CVG is a simple, fast, green, highly selective, and ultrasensitive yetinexpensive method for the speciation analysis of Hg21 and MeHg. It is expected to have similarapplications in other analytical atomic spectrometric techniques.

A simple and compact flame atomic absorption spectrometer (FAAS) was constructed to carry outsimultaneous multielement determination of calcium and magnesium in water. In this instrumental system, ahandheld and computer-controlled charge coupled device (CCD) spectrometer was used as the detector, anda calcium and magnesium multielement hollow cathode lamp was used as the light source. The instrumentallimits of detection (LOD) were 0.5mgl-1 and 0.03mgl-1 for calcium and magnesium, respectively. Calciumand magnesium in a water sample were simultaneously determined, with the analytical results in goodagreement with those by inductively coupled plasma optical emission spectrometry (ICP-OES). Therecoveries for calcium and magnesium standards added to the water sample were in the range of 103-114%.

In the traditional chemical vapor generation system of KBH4 (or NaBH4)–Cd21–HCl in aqueous solution,volatile components containing cadmium species can be generated but with low efficiency. In this work, it wasfound for the first time that the efficiency for the generation of the cadmium-containing vapor was greatlyimproved when halogenate, i.e., NaBrO3 or NaIO3, was added. The chemically generated vapor was separatedfrom the reaction medium, and introduced into an atomic fluorescence spectrometer (AFS) with argon as thecarrier gas, for the atomization and detection of cadmium. The experimental conditions for the efficientgeneration of the cadmium-containing vapor were optimized and the limit of detection (LOD, 3s) was thenfound to be 10 pg mL21. This modified chemical vapor generation system is potentially cleaner, and could havewide applications for sample introduction and/or matrix separation in analytical atomic spectrometries, such asflame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ETAAS),inductively coupled plasma atomic emission spectrometry (ICP-AES), ICP-MS (mass spectrometry), microwaveinduced plasma atomic emission spectrometry (MIP-AES) and MIP-MS for the determination of ultratracecadmium or some other elements.

Hydride generation atomic fluorescence spectrometry was for the first time utilized to determine trace toxic element arsenic in the skeleton fossils of four dinosaurs unearthed in Sichuan Province of China. The instrumental limit of detection (LOD) for arsenic was 0.03 mgyL under optimal experimental conditions, which compared favorably to that by ICP-AES and ETAAS. The samples were digested with aqua regia in boiling water bath. The recoveries of standard addition were found to be from 97 to 109%, and the analytical results were found in good agreement with those by ICP-AES. It is a simple, reliable, sensitive yet relatively inexpensive analytical method, compared to ICP-AES, ICP-MS or ETAAS. Interesting analytical results were found that the arsenic concentrations were all abnormally high in the skeleton fossils. The established analytical method and the analytical results may be helpful in revealing the mystery of the mass extinction of the dinosaur fauna. The analytical results, together with other data available to date, supported the argument that the arsenic toxicosis could be a contributing factor for the mass extinction of the dinosaur fauna in Sichuan Province of China.

Permanent chemical modifiers have been shown to prolong graphite tube lifetime while reducing the furnace cycle time, thus improving cost-effectiveness. In this work, iridium is used as a permanent chemical modifier for the first time in the determination of selenium by tungsten-coil atomic absorption spectrometry ŽW-Coil AAS.. The iridium modifier is thermally coated onto the tungsten coil. After coating, the coil can be used for 300-400 firings without further application of the modifier. Thermal treatment with iridium permits operating with higher pyrolysis temperature and coil lifetime is extended up to 1600 firings. The sensitivity and linearity of the method is improved, and the analytical procedure allows the use of analyte solutions containing up to 8% nitric acid. The short-term stability of the absorbance measurements is demonstrated by the reproducibility in the measurements of a Se amount 6ng. 30 times higher than the limit of detection Ž0.2 ng.. A 7% relative standard deviation ŽR.S.D.. was observed for 10 consecutive measurements of 6 ng Se. The long-term stability is almost as good: less than 9% R.S.D. over a 3-week period and 1500 firings. The surface of the tungsten-coil treated with iridium is examined before and after intensive use by scanning electron microscopy. Finally, the thermal treatment of the tungsten-coil with iridium appears to delay the appearance of selenium atoms by approximately 0.2 s although the integrated absorbance measurements are unaffected. The magnitude of delay decreases with coilage.

The techniques of field analytical chemistry _FAC. have the potential to reduce both analysis time and cost byproviding analytical data on site while eliminating the need for sample collection and transport. These methods couldbe of considerable interest in the fields of environmental monitoring and industrial process control. Much of FAC isaccomplished through the use of portable analytical instruments. The emphasis of this review was on field-portableatomic spectrometry, with particular focus upon two techniques: laser-induced breakdown spectroscopy _LIBS. andtungsten coil atomic absorption spectrometry _W Coil AAS.. LIBS and W Coil AAS have been described in detail,with special attention to instrumentation, analytical performance, applications and examples of portable devices. Thetwo techniques were compared and found to be complimentary. Competing technology, not necessarily based uponatomic spectrometry, was also briefly discussed in order to provide a glimpse of the overall picture of FAC techniquesused for the determination of metals. These rival techniques include X-ray fluorescence spectrometry _XRF.,immunoassay, capillary electrophoresis _CE., and electrochemical sensors.

A pulsed (10 Hz) optical parametric oscillator (OPO) lasersystem based on