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A highly sensitive spectrophotometric determination of cationic surfactants in ground waters was established by forming their Cu(II)–TPPS aggregates, preceded by solid-phase extraction with an SCX cartridge. Cationic surfactants (CSs) were quantitatively trapped and isolated by the SCX solid phase. The use of Cu(II)–TPPS anionic chromophore could reduce the interference by unintentional metal ions coexisting in surrounding waters. The method was very sensitive in the determination of CSs less than 10 −5 M levels with acceptable recovery and calibration data. The colorimetric sensitivity was very dependent on the alkyl-chain length of the surfactants, and a CS having 23 carbon atoms gave the highest sensitivity. Overall recoveries were 95–97% with R.S.Ds. less than 3% in the cases over 10 −6 M levels. In the cases in 10 −7 M levels, however, a portion of the analyte would be adsorbed by reservoir walls, which could seriously affect the trace determination. The preliminary addition of 4,4′-bipyridyl into the sample solution was effective in decreasing such unintentional analyte losses, leading up to 73% recovery. The developed method was applied to the analysis of river water at ppb levels of CSs with a fractional concentration through a SCX solid phase subjected by 500-mL aliquots of sample.

Commercially available but completely unknown surfactants used in the tin–lead plating industry were successfully identified by using electrospray mass spectrometry and NMR spectroscopy techniques, preceded by liquid ionization mass spectrometry used to obtain the preliminary information. The mass spectral data suggested that ethoxylated nonionic surfactants having a homologous distribution of molecular weights like 520, 564, 608, 652, 696, etc. were present. The NMR data suggested the presence of two aromatic rings and a quaternary carbon for the hydrophobe moiety instead of the well-known alkyl chains or alkylphenols. The unknown surfactants were finally concluded to be novel nonionic 4-(α,α-dimethylbenzyl)-phenol ethoxylates.

A non-suppressed ion chromatographic (IC) system for the high-sensitivity detection of common anions was developed using sulfoisophthalic acid as the eluent. The detection sensitivity was ten times higher than that using conventional non-suppressed IC with sodium phthalate as eluent, and was almost the same as that using conventional suppressed IC with a carbonate-hydrogencarbonate eluent under the same electrical conditions with a conductivity detector. Temperature regulation was very important in minimizing the baseline drift. A commercial incubator, in which a separation column and a sample injector were placed, was useful. The developed non-suppressed system facilitated the determination of low concentrations of phosphate, chloride, bromide, nitrate and sulfate at micromolar levels.

Phospholipids in middle ear effusion (MEE) and serum were analysed by liquid ionization (LI) mass spectrometry. The LI mass spectra of MEE and serum measured directly without preliminary separation commonly exhibited several unknown peaks such as those at m/z 520 and 577. These peaks were also observed in 90% ethanol fractions of MEE. The mass spectrum of the 90% ethanol fraction of serum exhibited dominant peaks at m/z 551, 577 and 603 (with mass differences of 26) and also at m/z 520. Comparing this spectrum with the mass spectra of standard compounds, the ions of mass 551, 577 and 603 were identified to be [M — phosphocholine] + of dipalmitoyl, palmitoyl-oleoyl and dioleoyl-glycero-3- phosphocholine (PC), respectively. The relative abundances of these ions observed in serum were qualitatively consistent with the composition of the fatty acid residue of PCs in serum determined by gas chromatography. The ions of mass 520, observed to be more abundant in MEE than in serum, were also identified to be [ceramide + — O], which is equal in mass to [M — phosphocholine] + , of N -palmitoyl-sphingo-phosphocholine (Sph). The results strongly suggest that a part of blood permeates into the middle ear cavity, and especially Sph does this easily. LI mass spectrometry is useful for analysis of phospholipids in biological samples.

A high-performance liquid chromatography method for the determination of linear alkylbenzenesulphonates (LASs) in river waters has been developed. The ppb levels of LASs can be determined by reversed-phase high-performance liquid chromatography with ultraviolet detection after on-line anion-exchange concentration and successive injection. LASs were quantitatively concentrated on the anion-exchange precolumn and easily cleaned up from river water matrix, because of its specific affinity, for the anion-exchange resin. A weak non-polar reversed-phase column was useful for the determination of LASs. The relationships between concentration andsummation of peak areas were linear from 10 to 200 ppb for total LAS concentrated from 5 ml of standard solutions. Overall recovery for total LAS was found to be 99%. Total LAS in the Tama River waters was determined to be around 100 ppb by the proposed method.

Liquid ionization (LI) mass spectrometry was applied to the determination of organic compounds in sweat. LI mass spectra of ordinary sweat exhibited characteristic peaks of lactic acid, urea and several kinds of amino acids. The relative peak intensities of these organic compounds changed according to the sweating rate. An unknown compound giving an intense peak at m/z 107 was found in sweat produced during walking excercise and was identified as diethylene glycol (DEG) by comparison with standard compounds. This identification was confirmed by liquid chromatography (LC). The concentrations of DEG in the sweat samples changed similarly to those of inorganic cations, depending on the change in momentum of the subject. The complementary use of LI mass spectrometry and LC is one of the best methods for the analysis of complicated organic mixtures such as biological fluids.

A cation-exchange chromatographic procedure for the simultaneous determination of urinary creatinine and aromatic amino acids is described. Creatinine and amino acids were separated from organic acids and/or neutral species in urine by using a preparative cation-exchange resin column. A column packed with a cation-exchange resin of low capacity was used for the analytical separations. The elution of creatinine and aromatic amino acids was monitored at 210 nm by means of an ultraviolet detector. The relationships between concentration and peak heights were reproducible with a coefficient of variation of less than 2%, and were linear from 5 to 200 microM for each compound. Overall recoveries of the analytes were more than 95%. The method was applied to the analysis of urine of patients with disorders of amino acid metabolism, such as phenylketonuria. The concentration ratios of phenylalanine to creatinine in the patients' urine were accurately and easily determined, and were quite different from those in the urine of healthy newborns.

Dye-sensitized photo-oxygenation of L-tryptophan (1) has been studied at various pH and in various buffers. Disappearance of 1 in both acetate and phosphate buffers was rapid at higher pH. The tricyclic hydroperoxide (8) was the sole product in the oxidation of 1 over the range pH 3.6–7.1 in acetate and phosphate buffers. However, the oxidation of 1 in alkaline phosphate and borate buffers (pH 7.7–8.4) gave 5-hydroxyformylkynurenine (10) as the major product. The intermediate, 3a,5-dihydroxypyrroloindole (16), which may be formed from the tricyclic hydroperoxide (8) via the quinoneimine (15), was obtained in good yield by the immediate reduction of the reaction mixture with NaBH4. Molecular oxygen (ground state) oxidation of 16 in the alkaline media provided 10. The similar oxidation and reduction of tryptamine (17a) gave 3a,5-dihydroxypyrroloindole (18b) which was not further oxidized to 5-hydroxyformylkynureamine. On the other hand, dye-sensitized photo-oxygenation of 1 in Na2CO3-AcOH (pH 7) gave formylkynurenine (3) as the major product.

The composition, formation constants, and molar absorptivities of the chelates of zirconium ion wtih xylenol orange and semi-xylenol orange are investigated spectrophotometrically in strong acid medium at ionic strength 3.0 (NaClO4 and HClO4). The data obtained were processed with a newly-constructed computer program and with LETAGROP/SPEFO. In the zirconium—xylenol orange system, Zr · H3 L, Zr· H4L, and Zr2 · L are present with logarithmic overall formation constants of 37.80, 38.68, 43.47, and molar absorptivities of 3.10 × 104 (485 nm), 5.98 × 104 (528 nm), 9.50 × 104 (551 nm) I mol-1 cm-1, respectively. The chelates Zr · L and Zr · HL were found in the zirconium—semi-xylenol orange system with logarithmic overall formation constants of 26.25 and 27.56, and molar absorptivities of 5.70 × 104 (532 nm) and 8.30 × 104 (535 nm) 1 mol-1 cm-1, respectively. Semi-xylenol orange is more sensitive and reliable than xylenol orange as a spectrophotometric reagent for zirconium.