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Accurate quantification of DNA is highly important in various fields. Determination of phosphorus by ICP-MS is one of the most effective methods for accurate quantification of DNA due to the fixed stoichiometry of phosphate to this molecule. In this paper, a smart and reliable method for accurate quantification of DNA fragments and oligodeoxythymidilic acids by hyphenated HPLC/ICP-MS equipped with a highly efficient interface device is presented. The interface was constructed of a home-made capillary-attached micronebulizer and temperature-controllable cyclonic spray chamber (IsoMist). As a separation column for DNA samples, home-made methacrylate-based weak anion-exchange monolith was employed. Some parameters, which include composition of mobile phase, gradient program, inner and outer diameters of capillary, temperature of spray chamber etc., were optimized to find the best performance for separation and accurate quantification of DNA samples. The proposed system could achieve many advantages, such as total consumption for small amount sample analysis, salt-tolerance for hyphenated analysis, high accuracy and precision for quantitative analysis. Using this proposed system, the samples of 20 bp DNA ladder (20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 300, 400, 500 base pairs) and oligodeoxythymidilic acids (dT12–18) were rapidly separated and accurately quantified.

A new coprecipitation method using iron hydroxide was developed to preconcentrate rare earth elements (REEs) in natural water prior to determination by inductively coupled plasma mass spectrometry (ICP-MS). The precipitate was collected in a syringe filter, which was connected into an ultrasound-assisted on-line elution and ICP-MS measurement system for REEs. Nitrogen (120 mL min−1) was mixed in auxiliary gas of ICP-MS to get rid of the oxide spectral interference with the REEs' measurements. When 10 mL of water sample was used, the blanks of REEs were from 0.001 pg mL−1 of Tm and Lu to 0.22 pg mL−1 of La and Ce. Detection limits calculated from 3-fold standard deviation of blanks were from 0.0006 pg mL−1 of Tm to 0.21 pg mL−1 of Ce. Recoveries of all REEs were from 97.1% to 103.1% with good reproducibility (standard deviation less than 3.3%). The usefulness of the method was confirmed by comparing the analytical results of NMIJ CRM 7201-a obtained with the present method and those obtained with an established solid-phase extraction method.

A method for the determination of iron in indium phosphide (InP) wafer is proposed. In the present experiment, an on-line matrix separation system using an ion exchange column was combined with inductively coupled plasma mass spectrometry (ICP-MS) for the determination of ng g−1 level of iron. In the on-line matrix separation, indium and iron in the sample solution was passed through a strongly-basic anion exchange resin column with the 9 M HCl carrier solution, where indium was eluted from the column and iron was adsorbed on it. Then, iron was eluted with the carrier solution of 0.3 M HCl containing 1 ng ml−1 cobalt, and it was directly introduced into the ICP-MS nebulizer. In ICP-MS measurement, cobalt in the carrier solution was used as an internal standard to correct the change in sensitivity due to matrix effect, and the peak area integration was performed to quantify iron and cobalt in the integration time range of 20–60 s from the start of the cobalt solution flow. The detection limit (3σ) for iron was 3 ng g−1, and the recoveries for iron in the 0.8, 2.4, and 8.0% indium solutions were almost 100%. The method was applied to the determination of iron in commercially available iron-doped InP wafers. The obtained results for InP wafer samples with the high iron concentration were in good agreement with those obtained by graphite furnace atomic absorption spectrometry (GFAAS).

A study on surface modification of an octadecylsilica (ODS) column with amphoteric surfactants has been carried out for efficient reversed-phase liquid chromatographic separations of hydrophobic analytes only with water eluent. Two amphoteric surfactants each with different terminal groups (betaine-type and sulfobetaine-type surfactants) were employed as the stationary phase modifier, and the separation characteristics of the modified ODS columns were evaluated by comparing the elution times of nucleosides, their bases, and inorganic ions. In both surfactant-modified ODS column systems, the adsorption of amphoteric surfactant led to a decrease in the retention of nucleosides and their bases, while an increase in the retention of inorganic anions. These results indicate that the amphoteric surfactant adsorbed on the ODS surface suppresses the hydrophobicity of the reversed-phase surface, but it also generates a specific electrostatic field. In other words, the modified ODS columns exhibit hydrophobic/electrostatic mixed-mode separation properties. The degree of the contribution of each property to the separation of analytes can be varied with the amount of the adsorbed surfactant. Consequently, nucleosides and their bases were effectively separated on the ODS column coated with 0.55 mmol of betaine-type surfactant in water elution.

The coastal seawater sample was filtered with a membrane filter (pore size 0.45 μm), and the filtrate was further filtered with an ultrafiltration filter (molecular weight permeation limit of 10000 Da). Then, major-to-ultratrace elements in the particles which remained on the membrane filter, the membrane-filtered seawater, and the ultrafiltered seawater were determined by ICP-AES (inductively coupled plasma atomic emission spectrometry) and ICP-MS (inductively coupled plasma mass spectrometry). From these analytical results, the fractional distributions of each element in the particle, large molecule and small molecule fractions of seawater were estimated, where the distributions of the elements in the large molecule fraction were obtained as the differences between the elemental concentrations in membrane-filtered and ultrafiltered seawaters. Furthermore, laboratory-made salts (Salts I—III) were prepared from original, membrane-filtered, and ultrafiltered seawaters. The concentrations of major-to-ultrat...

An amperometric detector with two working electrodes modified with polydiphenylamine (PDPA) and polydiphenylamine dodecyl sulfate (PDPA-DS) was successfully used for the simultaneous determination of electroinactive anions (SO42−, Cl−, NO3−) and cations (Na+, NH4+ and K+) in single-column ion-exclusion chromatography–cation-exchange chromatography (IEC-CEC). The PDPA-DS chemically modified electrode (CME) was based on the incorporation of dodecyl sulfate (DS) into PDPA by electropolymerization of diphenylamine (DPA) in the presence of surfactant. The electrochemical responses against the anions and cations in differential pulse voltammetry were studied. A set of well-defined peaks of electroinactive anions and cations were obtained. The relative standard deviations (RSDs) of chromatographic peak height (nA) for anions were all 0.990. Their detection limits were investigated using 3s (where s represents the standard deviation of a blank solution, n = 11). They were 9.86 × 10−7 mol L−1 for SO42−, 6.92 × 10−7 mol L−1 for Cl−, 7.86 × 10−7 mol L−1 for NO3−, 7.86 × 10−7 mol L−1 for Na+, 9.79 × 10−7 mol L−1 for NH4+ and 8.94 × 10−7 mol L−1 for K+. The recoveries of the anions and cations by this method were in the range 97.8–103%. The proposed method was rapid, sensitive and simple and was successfully applied to the analysis of rainwater samples. Both electrodes were stable during a 1 week period of operation with no evidence of chemical or mechanical deterioration.

An amperometric detector based on the chemical modification of poly-o-phenylenediamine (P-OPD) on a gold electrode was successfully used for the determination of electroinactive anions (SO42−, Cl−, NO3−, F−, CH3COO− and PO43−) by single-column ion-exclusion chromatography. All of the anions were detected conveniently and reproducibly in a linear concentration range of 1.0 × 10−5–5.0 × 10−3 mol L−1. The detection limits of the anions were 2.10 × 10−6 mol L−1 for SO42−, 2.47 × 10−6 mol L−1 for Cl−, 3.53 × 10−6 mol L−1 for NO3−, 3.41 × 10−6 mol L−1 for F−, 5.82 × 10−6 mol L−1 for CH3COO− and 3.86 × 10−6 mol L−1 for PO43− at a signal-to-noise ratio of 3. The proposed method was successfully applied to the analysis of rainwater and river water samples. The electrode was stable during a 2 week period of operation with no evidence of chemical or mechanical deterioration.

The determination of all rare earth elements (REEs) in human blood serum by inductively coupled plasma mass spectrometry (ICP-MS) was performed with the aid of chelating resin (Chelex 100) preconcentration after acid digestion with HNO3 and HClO4. When chelating resin preconcentration was carried out at room temperature, the recoveries of heavy REEs were lower than those of light REEs because of their stable complex formation with residual organic compounds remaining in the digested serum solution. These problems were overcome by heating the solution at 80 °C during the chelating resin preconcentration process. As a result, the recoveries for all REEs were improved to 92–102% in the case of a concentration factor of 4, where the analytical detection limits for REEs were below 0.2 × 10−12 g ml−1. Consequently, all REEs in individual human blood sera collected from five healthy volunteers could be determined by ICP-MS with good precision. The concentrations of REEs in human blood serum were extremely low, in the range from ca. 1 × 10−12 g ml−1 of Eu to ca. 230 × 10−12 g ml−1 of Ce.

The peculiar ion pairing elution behavior of anions with cations in electrostatic ion chromatography with water as eluent was investigated by using detectors based on conductivity and inductively coupled plasma-atomic emission spectrometry, where a sulfobetaine-type amphoteric surfactant (C14SB) immobilized on an octadecyl silica surface was employed as the stationary phase. Some preferential combinations of anions with cations were experimentally identified; Mg2+, for example, was preferentially paired with the anions in the order NO−3>Br−>NO−2>Cl−>SO2−4. The preferential combination characteristics could be used for the control of ion pair formation of analyte anions with counter cations. When MgSO4, used here as a “decoy electrolyte”, in which Mg2+ and SO2−4 were the “decoy cation” and “decoy anion”, respectively, was added to the original sample solution (Cl−, NO−2, Br− and NO−3 as analyte anions; Na+ K+, Mg2+ and Ca2+ as counter cations) at a relatively high concentration compared to the concentrations of analyte anions, all the analyte anions in the sample solution were eluted with the introduced decoy cation (Mg2+), following the preferential combination. Consequently, all the analyte anions were practically separated as a “decoy cation” form, and they could easily be determined from the calibration graphs of the anions in the decoy cation salts by conductivity detection. The present ion chromatographic method involving the characteristic anion–cation recombination technique was applied to the determination of anions (Cl−, Br−, and NO−3) in a vegetable (radish).

A combined system of size exclusion chromatography, UV absorption detection and ICP-MS was used for elucidation of the dissolved states of yttrium and lanthanide elements in lake water collected from Lake Biwa, Japan. The lake water samples were filtered with a membrane filter (pore size 0.45 µm) just after filtration with a glass filter (pore size 1.0 µm). The total concentrations of the dissolved lanthanide elements in the filtrate were determined by ICP-MS after chelating resin preconcentration. For speciation analysis, the above filtered water samples were further preconcentrated 30–500-fold with an ultrafiltration filter, which allowed preconcentration of molecules with molecular masses >10000. The preconcentrated sample solution was then subjected to speciation analysis using the above combined system, where a size exclusion column with the molecular permeation range between 1000 and 300000 was used for molecular separation. In the size exclusion chromatograms obtained with UV absorption detection at 254 nm, two peaks of some large organic molecules were obtained at retention times corresponding to molecular masses of >300000 (peak 1) and about 50000–10000 (peak 2). In the chromatograms, which were measured on-line by ICP-MS, yttrium and lanthanide elements (Y, La, Ce and Pr) were found at the two peak positions corresponding to above large organic molecules.

A new reversed-phase liquid Chromatographic (RP-LC) method for the separation of nucleosides and their bases using pure water as the mobile phase is described. A conventional octadecylsilica (ODS) stationary phase was used and modified with strong-positively/strong-negatively charged zwitterionic surfactants. When ODS is modified in this manner, hydrophobic interactions between the stationary phase (ODS) and the analytes (nucleosides and their bases) are reduced dramatically. Subsequently, if pure water is used for the mobile phase then an ‘effective’ distribution of the analytes between the stationary phase and the mobile phase can be achieved. It is proposed that the ODS is subjected to electrostatic fields produced by the positive and the negative charges in the strong zwitterionic surfactant. Furthermore, the hydrophobic interactions between the ODS and the analytes are greatly reduced by the electrostatic interactions emanating from these electrostatic fields. The practical applications of this and the possible mechanisms involved are described and discussed in this paper.

Ion Chromatographic separation of inorganic ions (anions and cations) was investigated by using three kinds of sulfobetaine-type surfactants (CHAPS, C12SB, and C14SB) as the stationary phases, which were coated by hydrophobic adsorption on the ODS column. In the present separation system, pure water was used as a mobile phase. Since the amount of surfactant adsorbed on the ODS surface significantly influenced the retention behaviors of inorganic ions, the amounts of the sulfobetaine-type surfactants adsorbed were estimated by the breakthrough procedure. The maximum amounts of CHAPS, C12SB and C14SB adsorbed were 0.40, 0.87 and 1.08 mmol, respectively. It was elucidated from the chromatograms of inorganic ions that the retention behavior of inorganic anions was directly related to the surface charges arising from the adsorbed surfactants. The large surface charge was effective for the efficient separation of inorganic ions in water elution. In addition, their retention behavior was strongly affected by the hydrophobicity of the adsorbed surfactants as well as the ionic functional groups of the surfactants which produced the charged surface. The elution order of inorganic anions was correlated with the Hofmeister series. This suggests that the hydration energies of the ions play important roles in separation in the water elution system.

A new approach for the simultaneous determination of inorganic cations and anions using ion chromatography was proposed. In this study, a zwitterionic stationary phase was employed with water as the eluent. With the ion separation achieved under these conditions, each anion species of the analytes could be separated from the others and eluted together with the analyte cations. The combination of the analyte anions with the analyte cations can be considered as an “ion-pairing-like” form and is briefly denoted as “ion pair”. If we determine all the ion pairs, the concentrations of the anions and the cations in the original solution can be calculated. This new approach for the simultaneous determination of inorganic cations and anions was investigated in this study.

The polymerization of pyrrole adsorbed on a roughened gold electrode was studied by surface enhanced Raman scattering (SERS) spectroscopy. It was found that pyrrole was polymerized at −0.2 V vs. SCE and under open circuit. It is concluded that the polymerization of pyrrole occurs by the catalytic action of adatoms on a roughened gold electrode because pyrrole is adsorbed with the molecular ring parallel to the surface plane.

Ion chromatography using a taurine-conjugated bile salt micelle-coated stationary phase has been investigated for the direct determination of common metal ions in biological samples. Taurine-conjugated bile salt micelles are reversed aggregates, where the negative charges of sulphonate form the inside of the micelle. The sulphonate charges are acting as the ion-exchange sites for the separation of cations, while the cavity of the helical micelle also act as a size-exclusion site for the rapid elution of large organic compounds. The combination of ion-exchange and size-exclusion functions provide a new model for the direct determination of inorganic species in biological fluids using ion chromatography. The present system was successfully used for the direct determination of sodium, potassium, magnesium and calcium ions in human's mixed saliva.

Organic UV-absorbing compounds such as α-amylase and tryptophan and inorganic UV-absorbing compounds such as nitrite, nitrate, iodide and thiocyanate contained in human saliva were simultaneously determined by ion chromatography using a strong-strong positively-negatively charged zwitterionic stationary phase. When both positive and negative charges are close together in a single molecule of the stationary phase, the postively-negatively charged zwitterionic stationary phase provides a specific retention behaviour for the separation of inorganic anions and organic zwitterions. It was demonstrated in previous experiments that the separation of inorganic anions and organic zwitterions is caused by simultaneous electrostatic repulsive and attractive interactions between the same and opposite charges. Separation of inorganic anions and organic zwitterions using ion chromatography based on simultaneous electrostatic attraction-repulsion interactions between the same and opposite charges has been termed “electrostatic ion chromatography’. This paper deals with a method for the improvement of the separation coefficient of electrostatic ion chromatography and a biological application.

Octadecylsilica coated with a micellar taurine-conjugated bile salt was investigated for the ion chromatography of inorganic cations. Monovalent and divalent cations could be separated by the proposed system, in which cerium(III) chloride was employed as the mobile phase component and the cations were determined by indirect UV-absorption measurement. The system was applied to the determination of inorganic cations in wine, isotonic beverage and water samples.

FT-Raman spectra of several platinum complexes were measured. Comparing the spectra of octahedral and square planar complexes, the intensity of Raman lines of Pt-ligand stretching vibrations of the former complex was stronger several times than that of the latter complex. As for the spectra of (PtX 2 (trans-d-dach), Pt-N stretching frequency decreased in the order of X=C 2 O 4

A continuous-microflow method with cold vapour atomic absorption spectrometric detection was used for the determination of mercury. A comparison of copper(II) and cadmium(II) salts as catalytic reagents is described in detail It was found that in the presence of at least 80 mg 1 −1 of copper(II) salt a similar signal was obtained for both inorganic mercury [mercury(II) chloride]and organic mercury [methylmercury(II) chloride]. With a cadmium(II) salt at least 100 mg 1 −1 were required.

A microcolumn liquid chromatographic method with cold-vapour atomic absorption spectrometric detection was developed for the speciation of mercury compounds in waste water. The sample solution containing mercury at the 4-ng level was injected onto a preconcentration column (27 mn × 0.51 mm i.d.) packed with Develosil-ODS (30 μm) and eluted with cysteine-acetic acid through a separation column (125 mm × 0.5 mm i.d.) packed with STR-ODS-H (5 μm). After oxidation, tin(II) chloride in sodium hydroxide solution was used to reduce mercury compounds to mercury. The generated mercury vapour was swept from a gas-liquid separator by argon into the detector cell and monitored at 253.7 nm. Mercury(II) chloride, methylmercury chloride and ethylmercury chloride, were well resolved and the determination was completed in less than 16 min. The method was successfully applied to the speciation of mercury compounds in waste water.

A method for the determination of ultratrace amounts of boron in high-purity tantalum materials [tantalum metal, tantalum(v) oxide, tantalum pentachloride and tantalum pentaethoxide] is described. On-line anion-exchange matrix separation combined with inductively coupled plasma mass spectrometry (ICP-MS) was employed for the determination of boron at the ng g(-1) level. Tantalum materials were dissolved using HF and/or HNO3 prior to analysis. The loss of boron in the sample preparation procedure was examined as the recovery of boron by adding a definite amount of boron to each tantalum material sample before decomposition, and it was almost negligible. In an anion-exchange method using 0.1 M HF carrier solution, tantalum and boron in the sample solution were first adsorbed on a strongly basic anion-exchange resin. Next, boron was eluted from the resin with 5 M HCl, whereas tantalum was retained strongly adsorbed. The eluted boron was introduced directly into the ICP-MS system for quantitative analysis at m/z 10 and 11. Because of the long elution time of boron, the transient signal was integrated in the time range 70-300 s on the chromatogram. Although the elution of boron in the time range was ca. 40% of total boron in the sample solution injected, the determination limits (10sigma) obtained by the present method were 30, 25, 15 and 13 ng g(-1) for tantalum metal, tantalum(v) oxide, tantalum pentachloride and tantalum pentaethoxide, respectively. The method was applied to the determination of boron in commercially available high-purity tantalum materials and it was found that the concentrations of boron were in the ng g(-1)-microg g(-1) range.

A method for the speciation of zinc and copper binding with proteins in human serum was explored by chelating resin (Chelex-100) pre-treatment and inductively coupled plasma mass spectrometry (ICP-MS). It was shown by a SEC (size-exclusion chromatography)-ICP-MS system that albumin-zinc and albumin-copper (loosely-bound species) could be selectively removed from serum by adsorption on the Chelex-100 resin after the chelating resin pre-treatment, while α2-macroglobulin-zinc and ceruloplasmin-copper (firmly-bound species) remained in the serum. The zinc and copper bound with α2-macroglobulin and ceruloplasmin, respectively, were then determined by ICP-MS after batch treatment of the serum samples with the Chelex-100 resin. In addition, the total concentrations of zinc and copper were also determined by ICP-MS after a 20-fold dilution with 0.1 M HNO3. The albumin-zinc and -copper were estimated as the differences between the concentrations of total and firmly-bound species. The present batch pre-treatment method was applied to the speciation analysis of zinc and copper binding with proteins in sera donated from 25 healthy volunteers as well as from a pregnant woman and a myelodysplastic syndrome patient. The observed concentrations of α2-macroglobulin-zinc and ceruloplasmin-copper were in the ranges 109–202 ng ml−1 (12.4–31.3% of total zinc) and 513–880 ng ml−1 (90.6–99.7% of total copper), respectively. The present method is simple (only addition of the chelating resin and centrifugation is required) and reproducible (average RSD = 2% for α2-macroglobulin-zinc and 1% for ceruloplasmin-copper in intra-assay measurements, and 5% for α2-macroglobulin-zinc and 4% for ceruloplasmin-copper in inter-assay measurements), and there is less risk of contamination during separation.

An automatic column changing system was developed for preconcentration and measurement of rare earth elements (REEs) in natural water samples, where syringe driven chelating columns (SDCCs) were applied to the hybrid (off-line operation and on-line operation) solid phase extraction of REEs. The sample loading was carried out off-line prior to the measurement. After that, the SDCCs were set into the column holder of the automatic column changing system and REEs were on-line eluted and measured by an inductively coupled plasma mass spectrometer (ICP-MS). The present automatic column changing system permitted continuously automatic measurement of 30 samples, while 3 min was enough for measuring one sample. The reproducibilities of REEs' signals obtained with two kinds of SDCCs showed that both of them are fit for the hybrid solid phase extraction method for preconcentration of REEs. The analytical detection limits (ADL) of REEs were in the range from 0.013 pg mL−1 for Tm to 0.15 pg mL−1 for Ce when 10 mL of water sample was loaded to each SDCC. The usefulness of the present method was confirmed by analysing NMIJ CRM 7201-a. After that, REEs in Lake Baikal water samples from depth of 50, 100, 150, 200, 250 m were determined. The results showed that dissolved REEs in the sample of 50 m depth were significantly lower than other samples, while the total REEs in the sample of each depth were close to one another. The distribution of REEs in Lake Baikal water samples was also discussed using shale normalized REEs distribution pattern.

This review paper is dedicated to the celebration of the 25th Anniversary of the Journal of Analytical Atomic Spectrometry (JAAS) published by the Royal Society of Chemistry (RSC). This means, of course, that the publication of JAAS started in 1985. On this occasion, we give our sincere congratulations to the past and present editorial board members of JAAS as well as to the editorial staff of the RSC for their efforts in maintaining the highest standards of the journal. We were asked to write our review paper introducing the history of analytical atomic spectrometry in Japan over the last 25 years to the present editorial board. Thus, this review will cover mostly the history of analytical atomic spectrometry in Japan after 1985. As for the historical aspects of spectrochemical analysis in Japan before 1985, it is recommended to refer to the following review paper by K. Fuwa and

In this paper, “metallomics” is proposed as a new scientific field in order to integrate the research fields related to biometals. Metallomics should be a scientific field in symbiosis with genomics and proteomics, because syntheses and metabolic functions of genes (DNA and RNA) and proteins cannot be performed without the aid of various metal ions and metalloenzymes. In metallomics, metalloproteins, metalloenzymes and other metal- containing biomolecules are defined as “metallomes”, in a similar manner to genomes in genomics as well as proteomes in proteomics. Since the identification of metallomes and the elucidation of their biological or physiological functions in the biological systems is the main research target of metallomics, chemical speciation for specific identification of bioactive metallomes is one of the most important analytical technologies to establish metallomics as the integrated bio-metal science. In order to rationalize the concept of metallomics, the distributions of the elements in man, human blood serum and sea-water, a challenge to all-elements analysis of one biological cell, and some other research topics are introduced with emphasis on recent development of chemical speciation of trace metals in some biological samples.

Batch treatment with Chelex-100 resin was investigated for preconcentration of trace metals in sea water followed by determination by inductively-coupled plasma atomic emission spectrometry. The preconcentration conditions such as resin weight, stirring time, and amount of ammonium acetate buffer solution were carefully examined for effective multi-element preconcentration from sea water. The resin weight could be decreased to 0.5 g (dry weight) for 1 l of sea water, which was much less than that required in the column method, and a preconcentration factor of 100 was achieved. Al, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Y, Mo, Cd and Pb in sea water were measured with good precision. The detection limits ranged from 6 to 180 ng l −1 . The time required for one sample by the batch method was only 3 h.

Temperature profiles of the “premixed” air-acetylene and argon-separated air-acetylene flames, produced with a capillary burner, have been investigated by a two-line atomic fluorescence method. The temperatures were obtained at a volume resolution of 0.3 × 2 × 5 mm3 in the flames. In an unseparated air-acetylene flame, temperature ranges from ca. 2600 to ca. 1900°K; the highest temperature (2650°K) was found 3 mm from the burner center and 60 mm above the burner head. In an argon-separated air-acetylene flame, temperature is in the range ca. 2500 to 1300°K; the temperature is the highest at the center and decreases rapidly towards the fringe of the flame (outer cone) due to the cooling effect of argon gas. In order to elucidate the analytical usefulness of the temperature profiles obtained, atomic fluorescence intensity profiles of Mg, Cu, In, and Cr have been also measured and discussed in detail.

Pulsed laser-excited molecular fluorescence of CaOH and SrOH in an air-acetylene flame have been investigated. The spectra were examined in the wavelength region from ca. 500 to 700 nm. A preliminary energy level diagram is proposed for CaOH. Results are also given for SrOH.

Coprecipitation with gallium hydroxide is studied for the preconcentration of trace metals in sea water before multi-element analysis by inductively-coupled plasma/atomic emission spectrometry. Gallium precipitates at pH 9 only when magnesium is present. Optimum conditions are established for multi-element preconcentration and removal of matrix elements. The method is almost free from contamination because of the use of highly pure gallium meetal and only a small amount of sodium hydroxide for pH adjustment. Spectral interferences from gallium are negligible and a concentratioin factor of more than 200 can be obtained. Detection limits range from a few ng l−1 to 150 ng l− for Al, Co, Cr, Fe, La, Mn, Ni, Ti, V, Zn, Y and Pb. Artificial and natural sea-water samples can be analyzed with adequate precision.

In order to characterize an atmospheric pressure helium microwave-induced plasma (M1P) and discuss the excitation mechanisms in the MIP, some spatial distributions of emission intensities of various species. of spectroscopic temperatures, and of electron number density have been determined for the helium M1P, and compared with those of the argon and mixed gas (helium/argon) MIP's sustained under the same operating conditions. The dependences of these parameters on the operating conditions of the M1P have been also examined. For the calculations of electronic excitation, rotational, and ionization temperatures, local thermodynamic equilibrium (LTE) in the M1P was assumed. However, these temperatures showed significant differences from each other. Based on the efficient excitation capability of the helium M1P, even for non-metallic elements, a metastable helium atom mechanism and/or a high-energy electron mechanism have been suggested here as the excitation mechanisms in the helium M1P.

A nondispersive vacuum ultraviolet atomic absorption spectrophotometer for mercury has been developed. A mercury electrodeless discharge lamp (EDL), which provided a significant radiant flux at both the main resonance line at 185.0 nm and the resonance-intercombination line at 253.7 nm, was utilized with a nitrogen-purged system and a CsI phototube. Because of its spectral response, the CsI phototube allowed it to measure effectively the mercury atomic absorption only at 185.0 nm. The dependence of the atomic absorption sensitivity on the EDL operational power was similar to that in a dispersive system. Since the nondispersive system allowed operation of the EDL with lower power compared with the dispersive system, better sensitivity could be obtained owing to less self-absorption of the resonance line. Furthermore, the low fluctuation noise of the light source led to a lower detection limit. The sensitivity and detection limit were 0.077 and 0.014 ng, respectively, and the relative standard deviation for 0.05 ng mercury was at most about 5.8%.

Spatially resolved radial distributions of excitation temperature and electron number density in an argon ICP were obtained. The argon excitation temperature and electron number density near the plasma center were found to 7000 K and 5 × 10 15 cm −3 , respectively, at an RF power of 1.5 kW and a carrier argon flow rate 0.65 1 min −1 . Various distributions of the absorbance at the Ar I 811.5 nm line, which has one of the metastable levels as the lower level, were obtained with and without carrier argon flow, where an MIP was used as a light source. Introduction of a large amount of potassium did not influence the distribution of the absorbance. The emission intensities at Ar I 811.5 nm were also measured for comparison.

Nucleotides, 5′-AMP, 5′-GMP, 5′-UMP, 5′-CMP and 5′-TMP, in D2O solution have been investigated by proton magnetic resonance spectroscopy. The concentration and the pD dependences of the proton chemical shifts of the nucleotides have been examined in detail. These results indicate that intermolecular association of vertical stacking of the base rings and intramolecular association between base protons and ionized phosphate group occur in solution. The effects of the temperature and lithium ion on 5′-AMP and 5′-UMP have been also investigated. The increase of temperature causes to reduce the intramolecular association for 5′-UMP and the both intra- and intermolecular association for 5′-AMP. Lithium ion reduces the intramolecular association for both 5′-AMP and 5′-UMP, and at the same time promotes the intermolecular one for the former. This can be interpreted by the ion-pair formation of lithium ion with the ionized phosphate group.

Laser-excited atomic fluorescence flame spectrometry with a pulsed nitrogen laser pumped tunable dye laser has been investigated with respect to analytical figures of merit, especially in terms of improvement of detection limits. The detection limits for 19 elements in an air-acetylene flame and for 5 elements in a nitrous oxide-acetylene flame are evaluated in the cases of both resonance and nonresonance atomic fluorescence lines. The detection limits obtained have been improved about 10 to 200 times. Detection limits for many elements excited by the frequency doubled dye laser output are reported for the first time. Now, most elements examined can be detected at the ng ml/sup -1/ (ppB) level or less with analytical curve linearities of over five orders of magnitude. Improvement of the detection limits was achieved mainly by expanding the diameter of the laser beam to illuminate a larger analyte volume in the flame and by using a low dispersive spectrometric system. The optical arrangement employed reduced the scatter signal and improved the signal-to-noise ratio (SNR). Although a low dispersive spectrometric system (spectral bandwidth of ..delta..lambda/sub M/) was employed, the spectral resolution of the system was determined by the spectral bandwidth of the laser, ..delta..lambda/sub L/(..delta..lambda/sub L/ muchmore » less than ..delta..lambda/sub M/). Conditions for optimizing analytical results are discussed. The results indicate that laser-excited atomic fluorescence spectrometry is potentially superior to atomic absorption spectrometry, atomic emission flame spectrometry, atomic emission induction coupled plasma spectrometry, and conventional source atomic fluorescence spectrometry, in terms of analytical figures of merit.« less

A micro-sampling technique, which requires sample volumes of less than 100 μl, is used for multi-element analysis by i.c.p. emission spectrometry. One drop of sample solution in a teflon cup is nebulized through a capillary tube. Internal standardization with yttrium improves the precision of measurement. The method is applied to the analysis of serum and whole blood samples, after dilution or digestion.

The determination of ultratrace levels of fluorine in bovine milk has been investigated by molecular absorption spectrometry using aluminum fluoride formed in an electrothermal graphite furnace. Aluminum (0.01 M, 20 μl, strontium solution (0.1 M, 10 μl) and milk sample (10 μl) were applied in the graphite furnace, and after drying and ashing, the furnace was heated at about 2700 K in 7s. Molecular absorption of aluminum monofluoride was measured at 227.45 nm, where simultaneous background correction was made with a deuterium lamp. The content of 0.033 μg F ml −1 was found for commercial bovine milk.

Molecular absorptions of monohalides ( MX; X  F, Cl and Br) of alkali metals, alkaline-earth metals and Group IIIB elements produced in a conventional electrothermal graphite furnace atomizer have been observed by a rapid measurement system. Their characteristic data are summarized as appearance and peak temperatures and the analytical sensitivities. Furthermore, molecular absorptions ofAlF and InF are utilized to study the interference of fluoride with aluminum and indium atomic absorptions. Although the formations of AlF and InF suppress the atomic absorptions ofAl and In, respectively, the time-overlap in signal appearance of atomic absorptions of these two elements and molecular absorptions of their monofluorides is not observed. This is contradictory to pure “vapor phase mechanism”, and indicates that processes occurring on the graphite surface are also important. Usefulness of strontium nitrate as a matrix modifier for the determination of indium was also demonstrated.

A silicon-intensified target vidicon tube (SIT) is evaluated for analytical use in the determination of 17 elements in an Ar-separated C2H2/air flame and 5 elements in an Ar-separated C2H2/N2O flame using combined atomic emission and atomic fluorescence as excited by a 150 W CW EIMAC xenon arc lamp. Benefits of combining emission and fluorescence signals in multielement analysis are experimentally shown. Limits of detection are approximately 100 times worse than previously reported by atomic fluorescence alone using a conventional spectrophotometer with the same 150 W EIMAC lamp. Linear dynamic ranges are between ∼10 and ∼100 for elements analyzed in the C2H2/air flame and are as high as 1000 for elements in the C2H2/N2O flame. Little or no use of the SIT and many similar image detectors for multielement analysis via atomic emission and/or atomic fluorescence is predicted at the present “state of the art.”

The emission lines of 10 non-metallic elements (H, C, N, O, F, Cl, P, S, Br and I) excited by an atmospheric pressure helium microwave-induced plasma have been tabulated with their relative intensities and transitions. These non-metallic elements were introduced into the plasma mostly as the vapor of organic compounds, although the emissions of H, N and O were observed due to the impurities in the helium gas. The spectral lines observed in the wavelength region from 190 to 850 nm were assigned with reference to established wavelength tables and tables of atomic energy levels. All emission line intensities of an element were normalized with respect to the most intense emission line of the element taken as 100.

Absorption spectra of alkali salts, which were aspirated into the air—acetylene flame, have been investigated in the u.v. and visible region, where a conventional atomic absorption spectrometer with an analog data processing system was used for obtaining the spectra. Molecular bands which arose from the alkali halides and oxides were observed along with atomic lines. In the case of lithium, only molecular absorption bands of lithium oxide were observed in the flame, even when lithium halides were aspirated. These molecular absorption bands can be interpreted in terms of photodissociation processes of the alkali halides and oxides produced in the flame.

An atmospheric pressure helium microwave-induced plasma (MIP) was combined with a gas chromatograph (GC). and used as an element-selective detector for GC. The detection limits, dynamic ranges and selectivities were obtained for H, C, F, Cl, Br, I and S. Such data for nitrogen and oxygen could not be obtained because of the interference from air which was entrained into the system through the leakages of the tubing and the valve system. The detection limits and dynamic ranges for all the elements investigated were in a range between 1.8 and 39pgs −1 and between 1.6 × 10 3 and 1.1 × 10 5 , respectively. Furthermore, the relative sensitivities of C, H, Cl and Br for various compounds were examined. In the cases of carbon and hydrogen, the relative sensitivities were not the same for different compounds containing oxygen and nitrogen. This result may be explained by the incomplete decomposition of such compounds due to the low microwave power (75 W) applied in the present system.

A method is described for simultaneous determination of 14 lanthanides and yttrium in monazites and xenotimes by inductively-coupled plasma atomic emission spectrometry. The ore samples were decomposed by heating with nitric acid/perchloric acid or hydrofluoric/nitric/perchloric acids, or sulfuric acid, or by fusion with sodium carbonate. Among these methods, treatment of the samples with sulfuric acid, by evaporation to dryness followed by dissolution of the residue with hydrochloric acid is recommended; it provided complete decomposition for the five monazites and xenotimes examined. The accuracy and precision of the results were significantly influenced by spectral interferences of the rare earth elements themselves; correction methods and factors are given. The chondrite-normalized rare-earth patterns were examined to characterize the monazite and xenotime samples.

A silicon-intensified vidicon target tube coupled to an optical multichannel analyzer has been evaluated as a detector system for inductively coupled plasma emission spectrometer. The silicon-intensified target detector was combined with a relatively high resolution monochromator to provide a simultaneous spectral monitoring capability over a 5 nm range. The detection limits obtained for 27 elements were at the nanograms per milliliter level in many cases. The detection limit data are compared to those of flame emission spectrometry using the same instrumental system, and also to those obtained by a commercial direct reading inductively coupled plasma system which utilizes photomultiplier detection.

Molecular fluorescence of PO produced in flames and excited by an Eimac xenon arc continuum source has been investigated. An SIT image detector combined with an optical multichannel analyzer (OMA) was used as the detector. Molecular fluorescence of PO could be observed near 246 nm in the air—acetylene, air—hydrogen, oxygen/argon—hydrogen, and the corresponding argon-separated flames, while PO fluorescence enhanced by molecular emission was observed in the nitrous oxide—acetylene flame and in the argon-separated nitrous oxide—acetylene flame. The fluorescence spectrum of PO near 246 nm is identical to the emission and absorption spectra of PO and is ascribed to the γ system, which is caused by the electronic transition A 2 Σ- X 2 Π. PO emission observed near 324 nm, a result of the transition D 2 Σ X 2 Π, was very weak in the present experiment and was not accompanied by measurable quantities of fluorescence. The fluorescence intensity of PO depends primarily upon the flame temperature, and so the quenching effect of nitrogen on the fluorescence intensity could not be observed. The best detection limit for phosphorus was obtained in the argon separated air—hydrogen flame, which generated the least amount of flame background noise, and was about 80 μg P/ml. Finally, because phosphine (PH 3 ) is an impurity in commercial acetylene, PO fluorescence bands in the 230–270 nm region may obscure the atomic fluorescence signals in this region excited via continuum sources and thus deleteriously affect atomic fluorescence signals in certain analyses.

The pD dependence of chemical shifts of the methylene protons in glycine and glycinepeptides (up to tetraglycine) in D2O solution has been investigated by proton magnetic resonance spectroscopy. The different kinds of the methylene protons in glycinepeptides show different chemical shifts. Furthermore, their chemical shifts significantly depend on the pD of the solutions, and reflect the dissociations of the carboxylic and amino groups. The chemical shifts of the methylene protons in peptides in D2O solution have been determined in the pD region from ca. 1 to 14. In addition, the dissociation constants, pK1 and pK2, in D2O solution are estimated from the present results as follows; pK1=2.84 and pK2=10.84 for glycine, pK1=3.74 and pK2=9.34 for diglycine, pK1=4.04 and pK2=9.04 for triglycine, and pK1=3.94 and pK2=8.94 for tetraglycine.

The spectral line profiles for emission lines of atoms and ions which were produced and excited in an inductively coupled argon plasma at atmospheric pressure have been measured by using an echelle monochromator. The emission line profiles of hollow cathode lamps were also measured to evaluate the resolving power of the monochromator and to deduce the instrument functions at various wavelengths. The line profiles were observed by a wavelength modulation technique; a quartz plate set just behind the entrance slit was modulated at 125 Hz and the photomultiplier output was acquired at 50 points with 2500 times integration for 20 s. The observed line profiles were simulated by the curve-fitting algorithm for the Voigt function, and a -parameters were deduced, after the instrument functions were corrected from the data obtained with the hollow cathode lamp measurements. The physical line widths, a -parameters, and Doppler temperatures obtained are in good agreement with those reported previously.

Absorption spectra of both atomic and molecular species in the air-acetylene flame, which are produced when the aqueous solutions of indium dissolved in HNO3, HF, HCl, HBr and HI were aspirated into the flame, have been investigated in the u.v. region. Numerous atomic absorption lines of indium have been observed in the absorption spectra. Most of these lines were previously listed only as emission lines. Those atomic lines have been ascribed to the electronic transitions from the ground states of 5p 2P 1 2 0 and 5p 2P 3 2 0 to the excited states such as ls 2S 1 2 , md 2D 3 2 , nd 2D 5 2 , 4p2 4P 1 2 , 4p2 4P 3 2 and 4p2 4P 5 2 , respectively, where 13 ⩾ l ⩾ 6 and 14 ⩾ m,n ⩾ 5. The molecular absorption bands for InF, InCl and InBr in the airacetylene flame have been also observed near 234 nm, 267 nm and 282 nm, respectively, as the electronic transition of 1Σ+ → 1Π1 Those absorption bands show fine structures due to the molecular vibrations. The spectral parameters for the molecular vibrations have been obtained from the simulations of the observed spectra. The molecular absorption band for InI was not observed because of the decomposition of the molecule in the flame. In addition, the molecular absorption band for InO has been observed near 273 nm and those for NO near 205 and 215 nm.

Flame emission determination of Sr in sea water is studied using an ordinary atomic absorption apparatus. The analytical line 4607 A is used with background correction at 4616 A. The ionization is found to be negligible in air acetylene flame with sea water, and the interference of H2SO4 is elimentated using the higher part of the flame.

Electrochemical preconcentration of trace metals on a graphite cup for multielement determination by inductively coupled plasma-atomic emission spectrometry (ICP-AES) is described, where controlled potential electrolysis of trace metals in an electrolyte solution similar to seawater has been examined by the use of a newly designed Teflon® cell to allow cathodic deposition. The characteristic of the present system is to make deposition of trace metals only inside a graphite cup, which is inserted into the plasma for the analysis by ICP-AES with the use of a computer-controlled graphite-cup direct-insertion technique. The electrolysis parameters and the solution circulation rates during electrolysis and washing of deposit have been optimized by a univariate search method. With the present experimental system, it is possible to preconcentrate trace metals by a factor of 30 to 300, and to separate them from the major matrix consituents, such as NaCl, KCl, and MgCl2, in artificial seawater. The detection limits for Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn at the pg/mL level can be obtained with relative standard deviation of 2 to 11%.