分光光度法测定水合肼技术性因素的研究

针对现行肼测定的标准分析方法(水质肼的测定-对二甲氨基苯甲醛分光光度法HJ674-2013)影响测定质量的因素,以实际测定为依据,从分析方法和统计学方法出发,研究和论述了校准曲线的建立、方法的测定范围、被测定样品的取样方式等几个方面,对分析测定及测定结果造成的影响。结果表明,分析方法的校准曲线建立方式会对校准曲线的质量和精密度产生很大影响,最终将影响到样品测定的准确性;测定范围将会影响到方法的适用性;方法中不正确的取样方式,不仅影响到样品测定的准确性,同时也使溯源性受到影响。本文给出的建议,可对方法的应用和修订提供技术支持。     

Simultaneous Ultraviolet Spectrophotometric Determination of Nitrate and Nitrite in Water

Abstract

A rapid and accurate method for the direct simultaneous determination of nitrate and nitrite is proposed. The method is applied to the determination of nitrate and nitrite in rainwater and wastewater without preliminary separation. The determinations are performed by a CPA matrix method with ultraviolet spectrophotometric detection. The results obtained are in agreement with those obtained by conventional methods for the determination of nitrate and nitrite.     

Simultaneous Determination of Total Nitrogen and Metal Elements in Tobaccos by High Performance Ion Chromatography

A simple method, developed primarily for simultaneous determination of total nitrogen and inorganic cations by high performance ion chromatographic (HPIC), was optimized for digestion of flue‐cured tobaccos, and compared with the traditional Kjeldahl method and atomic absorption spectrometry (AAS). Nitrogen determination by either Dumas method or Kjeldahl method is time‐consuming and tedious. Metal elements determination by either inductively coupled plasma‐mass spectrometry (ICP‐MS) or AAS may be more expensive and requires specialist equipment. The use of HPIC to simultaneous determine total nitrogen as ammonium ion and metal elements as inorganic cations after sample digestion significantly improves the speed of the analysis compared with the conventional methods. The cation‐exchange column and suppressed conductivity detector was used for determination of ammonium and inorganic cations in the presence of the elevated levels of sulfuric acid found in digested sample. The propsoed digestion method was accurate and precise, and required little investment. The determination of ammonium and inorganic cations was linear from 15 pg·L^?1 up to 25 ng·L^?1. The results obtained by the HPIC method were compared with those for the conventional methods approach for the determination of total nitrogen and metal elements. The application of the HPIC method is also demonstrated for a variety of other plant samples matrices.     

Radiochemical analysis of90Sr in milk,soil and plants by solvent extraction

A universal and fast method of⁹⁰Sr determination in environmental matrices (raw and dried milk, plants, soils) has been elaborated. Solvent extraction method of daughter⁹⁰Y by tributyl phosphate was used. The method of strontium determination is compatible with determination of other transuranic elements (americium, plutonium) and there is no need to check the chemical yield of strontium.     

Kinetic-spectrophotometric method for the determination of trace amounts of bromide in seawater

A novel simple, sensitive and rapid kinetic-spectrophotometric method is proposed for the determination of trace amounts of bromide. The method is based on its catalytic effect on the oxidation of methylene blue (MB) by hydrogen peroxide in strongly acidic solution. The oxidation reaction is activated by large amounts of chloride and can be monitored spectrophotometrically by measuring the decrease in the absorbance of MB at 746 nm. The determination of bromide is performed by a fixed-time method at the first 100 s from the initiation of the reaction. Unlike other kinetic-spectrophotometric methods for the determination of bromide, the proposed method does not require heating the solution. Bromide can be determined in the range from 80 to 960 μg l⁻¹ with the detection limit of 35 μg l⁻¹. The relative standard deviation of ten replicate determination of 480 μg l⁻¹ bromide was 1.4%. The influence of potential interfering ions was studied. The proposed method was satisfactorily applied to the determination of bromide in seawater without interfering effect from chloride ion.     

PTFE capillary trap as a tool to monitor non-ionic surfactants in the aquatic environment

A method based on the separation of non-ionic surfactants (NS) in the PTFE capillary trap with final determination by the indirect adsorptive stripping tensammetry has been developed. The method is suitable for NS determination in river water, raw and treated sewage within the range of 2-10,000 μg l⁻¹. The sample volume varies between 0.1 and 50 ml depending on NS concentration, and the time necessary for a single determination is approximately 15 min. This is several orders of magnitude better than determination with the recommended BiAS method. In environmental samples, recoveries ranges from 81 to 95% and precision ranges from 3 to 10%.     

Kinetic spectrophotometric method for rapid determination of trace formaldehyde in foods

A simple and sensitive kinetic-spectrophotometric method was developed for the determination of ultra trace amount of formaldehyde in food samples. The method was based on the oxidation of rhodamine B (RhB) by potassium bromate in sulfuric acid medium (formaldehyde as catalyst). The reaction was monitored by measuring the decrease in absorbance of the dye at 515 nm after 6 min. The developed method allowed the determination of formaldehyde in the range of 10–100 μg L⁻¹ with good precision, accuracy and the detection limit was down to 2.90 μg L⁻¹. The relative standard deviations for the determination of 10 and 60 μg L⁻¹ of formaldehyde were 3.0% and 1.9% (n = 10), respectively. The method was found to be sensitive, selective and was applied to the determination of formaldehyde in foods with satisfactory results.     

Quantitative evaluations of surface-concentrated amino groups on monolithic-type solid supports prepared by copolymerization method

We have prepared novel monolithic-type highly cross-linked solid supports having surface amino group using a copolymerization method of functional monomers and cross-linking monomer. From the view point of controlled surface functionalities, we have firstly certified and proved quantitative determination methods of the surface amino groups to utilize and evaluate those solid supports prepared as affinity resins. We utilized a typical titration method and ninhydrin method that have been effectively utilized for quantitative determination of primary amine and amino acid. The ninhydrin method was calibrated using octylamine as a standard compound (R ² = 0.998) and proved applicability for the quantitative determination of other primary amines. A commercially available solid support, Affigel, was able to be quantitatively evaluated only by the ninhydrin method, while Toyopearl afforded just compatible amino group density to the value certified by the manufacturer only through titration method. The obtained incompatible results using both determination methods have been unclear at this moment. On the other hand, both determination methods afforded compatible amino group density of the prepared solid support. The obtained value was up to 126 μmol/ml, which was 94% of the calculated theoretical value based on the feed composition. The results suggested surface-concentrated introduction of amino groups. Based on the determination methods, especially ninhydrin method, we prepared the monolithic-type solid supports having various densities of surface amino groups and proved quantitative and surface-concentrated introduction of amino groups. Those amino groups were able to react with a relatively large ligand molecule, methotrexate, quantitatively and also with controlled density. The obtained results strongly suggest that the novel monolithic-type solid supports have possible advantages when we utilize those as affinity resins for target peptide analyses.     

Study on Chemiluminescence System of Potassium Permanganate-Sodium Hydrosulfite-Aminopyrine

A new flow injection Chemiluminescence method for the determination of aminopyrine was studied. It is based on the chemiluminescence reaction of potassium permanganate-sodium hydrosulfite-aminopyrine. The main factors which affect the determination were investigated. Under the most favorable conditions. The linear range for the determination of amimopyrine was 2.0×10^-7~8.0×10^-5g/mL,the determination limit was 6.0×10^-8g/mL,the relative standard deviation was 1.8% for 11 mesurements to 4.0×10^-6g/mL aminopyrine standard solution. This method has been applied to the determination of aminopyrine in medicine.     

Extractive Spectrqphotometric Determination of Vanadium Liith o-Aminobenzo-Hydroxamic Acid

Abstract

A new spectrophotometric method for vanadium determination is proposed. The method is based on the extraction in Adogen-toluene solution of the complex formed between V(V) and o-Aminobenzohydraxámic acid

The method allows determination of 50 to 110 μg of V(V). The error and the apparent molar absorptivity are 1.2% and 5.2 ± 10³ l.mol^?1. cm^?1 respectively. The interferences caused by foreign ions have been established. The method is applied with success to determination of vanadium in petroleum crudes.     

Application of neutron activation analysis for the determination of implantation profiles of phosphorus in semiconductor grade silicon

A method of the determination of concentration profiles of phosphorus in silicon by neutron activation has been elaborated. The lower limit of determination is of the order 10⁻¹¹ g P. Two groups of errors have been discussed. The suitability of autoradiography to the determination of concentration profiles has been demonstrated. Some applications of the method have been suggested.     

Determination of sodium and phosphorus in organophosphorus compounds by fast-neutron activation

A method is described for the determination of sodium and phosphorus using the NG-160 neutron generator and an automated pneumatic transport device. The reactions²³Na (n, p)²³Ne and³¹P(n, α)²⁸ Al are utilized for the determination of sodium and phosphorus, respectively. For the determination of sodium, hermetically sealed vials are indispensable. The time required for one determination is 6 to 8 min. A rapid method for the determination of macro-amounts of sodium against a phosphorus background is also described, leading to the general conclusion that isotopes with γ-quantum energies close to 0.51 MeV can be determined against a background of positron radiation sources in a well-type crystal.     

Kinetic Spectrophotometric Determination of Acetaldehyde

ABSTRACT

A method for determination of trace quantities of acetaldehyde based on its inhibition effect on the malachite green-sulfite reaction is described. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance at 613 nm by a fixed time method of 60 seconds. The method allows the determination of acetaldehyde in the range of 0.2-10 μg/ml. The limit of detection was 0.1 μg/ml and the relative standard deviation for ten determinations of 2 μg/ml acetaldehyde was 1.8%. The method is applied to the determination of acetaldehyde in chemical industrial waste water with satisfactory results.     

Simultaneous First-Derivative Spectrophotometric Determination of Nickel and Manganese Complexes with 2-(2-Pyridylmethyleneamino)phenol

Abstract

A method is proposed for the simultaneous determination of nickel and manganese by first-derivative spectrophotometry based on their reactions with 2-(2-pyridylmethyleneamino)phenol (PMAP) Schiff base. The method allows the determination of Ni and Mn in the concentration range 0.3–3.0 μg ml^?1 in mixtures with their ten-fold concentration ratio. The method has been applied for Ni and Mn determination in bronzes. To optimize the experimental conditions for spectrophotometric determination of Mn with PMAP stability constants at different pH values have been determined. A critical evaluation of the proposed method was performed by statistical analysis of the experimental data.     

A sequential injection cold-vapor atomic absorption method for the determination of total mercury

A sequential injection (SI) method for the determination of mercury via cold vapor atomic absorption spectrophotometry is presented. The method differs from flow injection (FI) cold vapor methods for the determination of mercury because of the simplicity of the system required for the method: one pump, one valve, a gas-liquid separator, and an atomic absorption spectrophotometer equipped with a quartz cell. Under optimal conditions, the method has the following figures of merit: a linear ¶calibration range of 1.0 to 20 μg L^–1; a detection limit of 0.46 μg L^–1; and a precision of 0.90% RSD (8 μg L^–1). The procedure allows for a sampling rate of one injection per 80 s (excluding sample pretreatment). Results from the determination of mercury in water and fish specimens are also presented. The figures of merit of the method are compared to two other SI methods for the determination of mercury.     

Batch and Flow Injection Fluorimetric Determination of Fluoxetine

Abstract

A method for the fluorimetric determination of fluoxetine in continuous and discontinuous systems is reported. The method is based on the hydrolysis of fluoxetine in acid medium. The fluorescent product has a spectrum with excitation and emission maxima at 253 and 306 nm, respectively. The method was applied to the determination of fluoxetine in pharmaceutical products.     

A modified radiometric method for plutonium determination in irradiated fuel

A modified radiometric method for the determination of plutonium in irradiated nuclear fuel is described. The analysis consists of total plutonium alpha-activity, activity ratio²³⁸Pu:(²³⁹Pu+²⁴⁰Pu) and burnup determination. The error of plutonium determination is practically identical with that of a classical radiometric method. The method suggested is suitable for large sample series of the same type of irradiated nuclear fuel.     

Ultrasound‐assisted emulsification microextraction based on a solidified floating organic droplet for the rapid determination of 19 antibiotics as environmental pollutants in hospital drainage and Gomti river water

Antibiotics that are used excessively and disposed of improperly are categorized as emerging pollutants. The determination of micropollutants in water with an accurate and precise method is always a big challenge. Hence, a simple, rapid, sensitive, economical and almost eco‐friendly method is proposed for the quantitative determination of 19 antibiotics. The proposed method, ultrasound‐assisted emulsification microextraction and solidified floating organic droplet coupled with liquid chromatography and triple quadrupole mass spectrometry, has only a 3 min chromatographic run time for the determination of the 19 antibiotics. We report for the first time the use of the developed method for the quantitative determination of the antibiotics in waste water samples with better results in terms of higher sensitivity, cost‐effectiveness, better detection limits and a greener approach compared to the earlier reported methods. The limits of detection and quantification were in the range of 0.003–0.236 and 0.013–0.834 μg/L, respectively, with good linearity in the concentration range of 0.01–64.0 μg/L. The correlation coefficient was ≥0.987–0.99 for each analyte. The developed method has been successfully applied for the determination of antibiotics in water samples.     

Indirect Determination of Organic Compounds by Atomic Absorption Spectrophotometry: The Study of Vitamin B12 in Pharmaceutical Dosage Forms

Abstract

A method for the determination of vitamin B₁₂ in pharmaceutical dosage forms is presented. The method involves, dissolution of the vitamin B₁₂ and subsequent determination of the complexed cobalt by atomic absorption spectrophotometry. The method is both rapid and sensitive giving applications to quality, control of this type of formulation.     

Microtitrimetric determination of salbutamol sulfate usingN-bromosuccinimide

A simple titrimetric method for the micro determination of salbutamol sulfate withN-bromosuccinimide is described. The method is simple, sensitive and can be utilized in the determination of salbutamol sulfate in microgram amounts. The results compare favorably with British Pharmacopeial method.