A rapid,simple method for the determination of total mercury in fish and hair by cold-vapour atomic absorption spectrometry

Fuming nitric acid and acidified potassium permanganate are used to pre-digest fish or hair samples in Pyrex culture tubes. Cold-vapour atomic absorption spectrometry is used to detect the elemental mercury which is generated by reduction in a syringe. The absolute detection limit of the method is 0.66 ng Hg, and at levels of 0.14 and 0.60 parts per million (ppm) the standard deviations are ± 0.009 and ±0.008 ppm, respectively. One person can handle batches of 50–100 samples per day including standards and blanks.     

A radiochemical neutron activation analysis method for the determination of total mercury in coal

A radiochemical neutron activation analysis method has been developed based on pyrolysis followed by double gold amalgamation for the determination of mercury in solid samples. Accurate results were obtained for mercury in six standard reference materials of varying matrices, including coal. Linearity was demonstrated up to mercury concentrations of 10,000 ng/g. The method is capable of yielding precise, reproducible values with a detection limit of 5 ng/g for mercury in coal.     

A simple and fast method for the determination of active ingredient in antiperspirant cosmetics by neutron activation analysis

Antiperspirant cosmetics are tested for their active ingredient (aluminium chlorohydroxide) by conventional analytical techniques. Aluminium has been determined by instrumental neutron activation analysis in all antiperspirant products and package forms available in the Greek market in order to develop a simple and fast method for its quantitation. Our results show that neutron activation analysis could be established as an official method for the determination of active ingredient in antiperspirant cosmetics. The proposed method is compared with the existing official methods and an alternative sampling method for aerosol package is presented.     

A low-cost non instrumental method for semiquantitative determination of mercury in fish

A non instrumental method for the semiquantitative determination of mercury in fish is described. The sample is acid digested and the mercury vapor released after chemical reduction with SnCl2. The mercury vapor is then collected on a detecting paper covered with an emulsion of Cu2I2, 3% carboxymethylcellulose and MgCl2 as moistener agent. The colored Cu2[HgI4] complex is formed and the color intensity is proportional to the mercury concentration in the original sample. Parameters such as sample mass/digestion solution volume ratio, emulsion composition, paper covering technique, carrier gas flow were investigated. Comparative studies using CVAAS and digital color analysis after scanning the papers confirmed the applicability of the method to real samples.     

A low-cost non instrumental method for semiquantitative determination of mercury in fish

A non instrumental method for the semiquantitative determination of mercury in fish is described. The sample is acid digested and the mercury vapor released after chemical reduction with SnCl₂. The mercury vapor is then collected on a detecting paper covered with an emulsion of Cu₂I₂, 3% carboxymethylcellulose and MgCl₂ as moistener agent. The colored Cu₂[HgI₄] complex is formed and the color intensity is proportional to the mercury concentration in the original sample. Parameters such as sample mass/digestion solution volume ratio, emulsion composition, paper covering technique, carrier gas flow were investigated. Comparative studies using CVAAS and digital color analysis after scanning the papers confirmed the applicability of the method to real samples. Received: 3 July 1999 / Revised: 29 September 1999 / Accepted: 21 October 1999     

A novel,simple and robust method for the analysis of sulfonamides in fish farming water samples using column switching liquid chromatography

A novel method for the online extraction and preconcentration of four sulfonamides was developed using column switching liquid chromatography. Sulfadiazine, sulfathiazole, sulfamethoxypyridazine and sulfamethoxazole were analysed in water samples and preconcentrated in a C18 guard column. Suitable validation parameters were obtained, such as precision, accuracy and relative recovery, in accordance with the validation guidelines of the Food and Drug Administration. Low limits of detection (0.05–0.09 µg L^?1) and quantification (0.30 µg L^?1, for all of them) were obtained. The quadratic polynomial model was used to adjust the calibration data, and the coefficients of determination were higher than 0.999 for all the analytes. The method was shown to be robust to the assayed parameters according to Youden’s test. The proposed method was successfully used to determine sulfonamides in 11 different fish farming water samples, in which sulfadiazine (0.732 µg L^?1), sulfamethoxazole (0.531 µg L^?1), sulfathiazole (0.546–1.856 µg L^?1) and sulfamethoxypyridazine (0.369–1.509 µg L^?1) were found.     

Low level mercury analysis by neutron activation analysis

During the years 1974–77 about 200 low level mercury analyses on samples with less than 1000 ng Hg/kg were made at the Danish Isotope Centre. This paper describes our method of neutron activation analysis for low level mercury analysis. The accuracy of the mercury analyses is shown by the results of the determinations on NBS standard, SRM 1642, and on intercalibration analyses. The accuracy found is better than 10% for samples with about 100–300 ng Hg/kg and better than 10 ng Hg/kg for samples with less than 100 ng Hg/kg. The limit of detection for the analyses is about 1–5 ng Hg/kg, depending on the sample and the exact method of analysis. The lowest standard deviations on duplicate analyses are about 1 ng Hg/kg. The general level found in sea water is about 10 ng Hg/kg, in ground water about 50 ng Hg/kg, and in rain water about 100 ng Hg/kg.     

Determination of mercury,arsenic and cadmium in fish by neutron activation

Determination of mercury, arsenic and cadmium in fish has been carried out by neutron activation followed by chemical separation to remove the interfering activities of copper, zinc, etc. Some of the common varieties of fish have been analysed and their results are presented.     

A study of the iodinated resin column for the determination of iodine in biological fluids by radiochemical neutron activation analysis

The iodinated resin technique for separation of¹²⁸I directly from neutron irradiated biological fluids is attractive due to its rapidity, simplicity and high degree of radiochemical purity; however, some doubts exist about the yields of iodine which can be recovered, particularly from organically bound iodine. In the present study, chemical yields on the resin column were studied for irradiated urine, serum and milk by standard additions of iodide and thyroxine. It was found that yields are not quantitative but lie in the range 80–95%, depending on the matrix, with a variability of up to 6% standard deviation. In addition it was shown that no significant adsorption of iodine occurs on polythene ampoules from irradiated biological fluids of natural pH. Some comparative experiments between the resin technique and the oxygen flask ignition method on fluids before or after drying, respectively, showed satisfactory agreement. It is concluded that the iodinated resin technique is suitable for routine analyses or large scale screening programs.Presented in part at SAC 83, Edinburgh, July 1983.     

Determination of mercury in air by neutron activation analysis

A sensitive method for the determination of mercury in sea and surface waters is presented. A distinction is made between inorganic, organic and particulate mercury. In the determination of inorganic mercury, the element is isolated by reduction and volatilization, followed by absorption on a charcoal column. The total mercury content of the water with and without suspended solids is determined by absorption from the solution onto a column of charcoal. In all cases, the mercury on the absorber is determined by thermal neutron activation analysis. The limit of detection is l ng 1^-1.     

Determination of mercury in bismuth by neutron activation analysis

A method has been developed for the determination of traces of mercury in bismuth by neutron activation analysis. After sample irradiation at a flux of 7 · 10¹³ n cm^-2 s^-1 for 20 min, mercury was separated from bismuth by addition of ammonium sulfide and re-dissolution of bismuth (matrix) sulfide with nitric acid, and filtration of sulfur containing mercury on a membrane filter. The activity of the 68- or 68–77-keV region, counted with a Ge(Li) or NaI(Tl) detector, was used for quantitative measurements. The method was applied to bismuth samples containing 0.1–100 p.p.m. of mercury.     

Substoichiometric determination of mercury by neutron activation analysis

A method has been developed for the substoichiometric determination of mercury by thermal neutron activation analysis, based on the selective extraction of the Hg(II)—Bindschedler's Green complex into 1,2-dichloroethane. The method has been applied for the determination of trace amounts of mercury in geological standards such as W-1, GR, Sye-1, and T-1, meteorite Allende de Publito, and biological materials such as kale, IR1 standard tobacco, and human blood serum.     

A simple apparatus for the determination of mercury by amalgamation with gold

The method of Eschka for the determination of mercury by amalgamating with gold has been modified by using a simple apparatus which eliminates errors caused by loss of mercury vapour. The method does not require a skilled operator and it is suitable for routine analysis. For a sample containing 3% mercury, the estimated standard deviation is 0.06.     

A simple oxidation procedure for biological material prior to analysis for mercury

The stability constants of aluminium(III), gallium(III), indium(III) and scandium(III) with 8-hydroxyquinoline and its 2-methyl derivative have been determined by potentiometric titration, with computation by the SCOGS program. In contrast to previous work, the results show that protonated species occur in several of the equilibria. The constants are discussed in terms of the nature of metal-to-ligand bonding in the complexes. X-ray photoelectron spectroscopy of the ligand coordinating atoms in the solid complexes confirms the significantly increased covalency of the gallium—oxygen bond compared to the same bond in the aluminium complex.     

A simple and highly efficient method for the synthesis of chalcones by using borontrifluoride-etherate

Chalcones are secondary metabolites of terrestrial plants, precursors for the biosynthesis of flavonoids and exhibit various biological activities. Condensation of substituted acetophenones (2a-12a) with various aromatic aldehydes (1b-7b) in the presence of BF₃-Et₂O at room temperature gave chalcones in 75-96% yield.     

Epithermal neutron activation analysis using the monostandard method

A method is described for epithermal neutron activation analysis of 17 elements in granite rock samples using a single standard. Gold has been used as a single comparator due to its relatively high resonance integral value (I₀=400 barn). In addition, it is preferable to Co in order to obtain a large epithermal activation in a short irradiation. The method of calculation is simple and rapid and can be done using a small calculator. Epithermal activation is able to overcome the difficulty arising from changing irradiation position as well as increasing the number of determinable elements by eliminating the interference from undesired isotopes which have relatively high thermal cross section values (₀), when reactor neutron flux is used. The coupling of epithermal activation with the monostandard method has the advantage of using a small Cd-cover which overcomes most of the difficulties arising in the relative method with large volume cadmium filters.     

A simple gas chromatographic method for the analysis of oxygenates in gasoline

Chromatographia - A number of oxygenated compounds such as C1?C4 alcohols, methyl tert-butyl ether (MTBE), and tertamyl methyl ether (TAME) are increasingly being used in gasoline as octane...     

A simple gas chromatography method for the analysis of monoethanolamine in air

A simple method determining airborne monoethanolamine has been developed. Monoethanolamine determination has traditionally been difficult due to analytical separation problems. Even in recent sophisticated methods, this difficulty remains as the major issue often resulting in time-consuming sample preparations. Impregnated glass fiber filters were used for sampling. Desorption of monoethanolamine was followed by capillary GC analysis and nitrogen phosphorous selective detection. Separation was achieved using a specific column for monoethanolamines (35% diphenyl and 65% dimethyl polysiloxane). The internal standard was quinoline. Derivatization steps were not needed. The calibration range was 0.5-80 μg/mL with a good correlation (R(2) = 0.996). Averaged overall precisions and accuracies were 4.8% and -7.8% for intraday (n = 30), and 10.5% and -5.9% for interday (n = 72). Mean recovery from spiked filters was 92.8% for the intraday variation, and 94.1% for the interday variation. Monoethanolamine on stored spiked filters was stable for at least 4 weeks at 5°C. This newly developed method was used among professional cleaners and air concentrations (n = 4) were 0.42 and 0.17 mg/m(3) for personal and 0.23 and 0.43 mg/m(3) for stationary measurements. The monoethanolamine air concentration method described here was simple, sensitive, and convenient both in terms of sampling and analytical analysis.