38results about How to "Low blank value" patented technology

A method for detecting cadmium content in cigarette used tipping paper is characterized in that the method can quickly and accurately detect the cadmium content in the cigarette used tipping paper by the following steps: adopting mixed acid to carry out microwave digestion for a sample, removing the acid and fixing volume, conducting detection with a graphite furnace atomic absorption spectrophotometer, etc. The method overcomes the shortcoming of the prior art in processing the sample. Compared with the traditional electric heating plate digestion manner, the microwave digestion manner can reduce the usage of samples and strong acid, improve digestion ability, cause less loss to elements to be detected in the sample and less damage to an operator, and facilitate operation. The digestion system of compound acid is completely applicable to the special material of the cigarette used tipping paper. The acid removing process is quick and easy, and a matrix modifier is adopted to eliminate interference. After being detected by optimal heating up programs, ashing temperature and atomization temperature related to atomic absorption spectrometry, the special material of the cigarette used tipping paper is recovered with high rate, and detected with accurate result. The working efficiency and the economic benefits are significantly improved.

The invention discloses a method for simultaneously determining harmful elements in iron ore. The method comprises the following steps of: processing a sample through microwave digestion; under optimized instrument working conditions, drawing a standard curve by a standard addition method to correct the matrix effect; and simultaneously determining the harmful elements including sodium, potassium, lead and zinc in the iron ore by use of an inductive coupling plasma mass spectrometer. Through the invention, the problems of complicated operation and processing steps, low sensitivity, low stability, poor reproducibility and the like in the former determining process are solved; and the method disclosed by the invention has the characteristics of fast determination, high sensitivity and accurate result, and is favorable for environmental protection and human health.

A method for detecting the As in food, health-care food, or biological specimen includes dissolving the specimen in nitric acid and hydrogenperoxide mixture under action of microwave, adding the mixed solution of 150 g / L thiourea and 100g / L VC, mixing, taking 25ml solution laying aside at orinary temp for 40-50 min, and atomic spectrofluorimetry. Its advantages are high speed, correctness and sensitivity.

The invention relates to a method for testing the content of mercury in tipping paper for cigarette, which comprises using 3% hydrochloric acid to do constant volume to a certain volume after a tipper paper sample for cigarette is digested by mixed acid, utilizing sodium borohydride which contains sodium hydroxide to be reducing agent in the environment of strong acid-hydrochloric acid, deacidizing mercury in an ionic condition to elemental mercury, utilizing argon gas to be a carrier, and blowing vapor with mercury atoms under normal temperature in a cold atomic absorption spectrometry instrument to measure. Mercury atoms have a strong absorption function to a resonance line whose wavelength is 253.7nm, and the relationship between the size of absorption and the concentration of mercury atoms is in accordance with the beer law in a certain concentration scope, and the mercury atoms are compared with standard series to do constant volume. The method overcomes the shortcomings of the sample handling method in the prior art, which optimizes the concentration of acid, sodium borohydride and sodium hydroxide and the flow of carrier gas (argon gas) in a flow-injection cold atomic absorption spectrometry instrument. The invention has the advantages of simple operation, quick speed, accuracy, excellent sensitivity and repeatability.

The invention discloses a pretreatment method for determining multiple heavy metal elements in soil simultaneously. The pretreatment method comprises steps as follows: step (1): sample weighing: the soil is air-dried, ground and screened with a nylon sieve, a soil sample is weighed and put into a microwave digestion tube through a polytetrafluoroethylene long-neck funnel, and the funnel is slightly flapped before the funnel is removed so that all the soil sample attached to the wall of the funnel enter the digestion tube; step (2): digestion: nitric acid, hydrochloric acid and hydrofluoric acid are added to the digestion tube, a cover is screwed down, and the digestion tube is put into a microwave digestion instrument for digestion; step (3): acid driving: after microwave digestion is finished, hydrogen peroxide is added to the digestion tube; then the microwave digestion tube is put into a temperature-controlling acid driver in a fume cupboard for direct acid driving until the volume is smaller than 1 mL, then a solution is directly transferred to a volumetric flask, the volume is constant, and a to-be-tested solution is obtained. With the adoption of the pretreatment method, the digestion speed of the sample can be increased, the pre-treatment step of the sample is simplified, and the accuracy of the detection analysis result is guaranteed.

The invention provides a method for determining iron content in nori with a flame atomic absorption spectrometry. The method comprises the following steps: dyeing a sample at a high temperature to remove water; immersing the sample into a digestion solvent for long time and then pre-treating under high-temperature, high-pressure and closed conditions, so as to rapidly transfer iron in the sample into the digestion solvent at maximum, wherein the digestion solvent is a mixed acid of nitric acid and perchloric acid at a volume ratio of 4:1; heating and digesting by using a microwave oven so as to achieve a high temperature instantly and shorten the digestion time. According to the method provided by the invention, the problems of a traditional method that the consumed time is long and the use amount of solvents is great when the flame atomic absorption spectrometry is used for determining microelements and the environmental pollution caused by the solvents is serious are solved; the method has the advantages of rapidness and convenience, good repeatability and good accuracy, and is applicable to determining the microelements of similar materials.

A magnetic signal measuring apparatus includes a first magnetic field applying unit that applies a first magnetic field to magnetic substances when a measured substance is binding to the magnetic substances, a second magnetic field applying unit that applies a second magnetic field to the magnetic substances to which the first magnetic field has been applied, and a SQUID that measures a magnetic signal derived from the magnetic substances. The first magnetic field has an intensity of such a degree that the magnetic substances do not flocculate with each other and such a degree that directions of magnetic moments in the magnetic substances can be aligned with each other. The second magnetic field has an intensity of such a degree that the magnetic substances do not flocculate with each other and such a degree that a magnetic signal can be obtained from the magnetic substances.

The invention discloses an environment-friendly high-efficiency acid reflux collection-type element analysis sample digestion method. The method comprises the following steps of: (1) preparing a digestion container equipped with an acid reflux collection device; (2) weighting 0.2 to 0.5g of a solid sample in the digestion container, and adding 2.0 to 21.0mL oxide to obtain a sample solution to be measured; (3) placing the digestion device equipped with the acid reflux collection device and containing the sample solution to be measured on an electric heating plate for digestion; (4) raising temperature of the electric heating plate to remove acid by evaporating after the sample is digested completely; and (5) taking down the digestion container, adding a small amount of deionized water or ultrapure water to dissolve salts, transferring and diluting to fix volume in a volumetric flask to obtain the to-be-measured solution. The digestion method provided by the invention is closed completely from the sample digestion to the evaporation acid-removal processes so as to avoid direct contact between the digested sample and ambient air and avoid pollution of ambient dusts to the sample in the digestion container, thereby greatly improving precision and accuracy of an analysis result.

The invention discloses a sampling membrane and a sampler capable of enriching heavy metals in ambient air and an application method of the sampler. The sampling membrane comprises a nanometer fiber membrane and an air-permeable supporting padding arranged below the nanometer fiber membrane. The sampler comprises the sampling membrane and a sampling clamp; the sampling clamp is composed of an upper cone and a lower cylinder, wherein the upper surface of the cone is horizontal, the cylinder is composed of an upper cylinder and a rotary lower cylinder, the side surfaces of the upper cylinder and the lower cylinder are provided with uniformly distributed vertical ridges, the vertical ridges on the upper cylinder and the lower cylinder are aligned by rotating the lower cylinder, so fixation of the sampling membrane on the horizontal surface of the sampling clamp is realized. After heavy metals in air are acquired by using the sampler, a filter membrane is taken out and put into a centrifuge tube filled with a buffer solution, a solution is used for desorption of the heavy metals on the filter membrane, and after desorption, the solution is determined. According to the invention, detection sensitivity can be substantially improved, pre-treatment of a sample is easy and feasible, and nanometer fiber filter membranes with different functions are used for different detection objects, thereby improving absorption and acquisition efficiency.

A method for detecting cadmium content in cigarette used tipping paper is characterized in that the method can quickly and accurately detect the nickel content in the cigarette used tipping paper by the following steps: adopting mixed acid to carry out microwave digestion for a sample, removing the acid and fixing volume, conducting detection with a graphite furnace atomic absorption spectrophotometer, etc. The method overcomes the shortcoming of the prior art in processing the sample. Compared with the traditional electric heating plate digestion manner, the microwave digestion manner can reduce the usage of the samples and strong acid, improve digestion ability, cause less loss to elements to be detected in the sample and less damage to an operator, and facilitate operation. The digestion system of compound acid is completely applicable to the special material of the cigarette used tipping paper. The acid removing process is quick and easy. After being detected by optimal heating up programs, ashing temperature and atomization temperature related to atomic absorption spectrometry, the special material of the cigarette used tipping paper is recovered with high rate, and detected with accurate result. The working efficiency and the economic benefits are significantly improved.

The invention provides a method for determining volatile phenol in water. In color reaction using 4-amino-antipyrine direct spectrophotometry to determine volatile phenol in water, the method uses Tween-80 as nonionic surfactant to play a role in stability augmentation and sensitivity enhancement, reduce system blank value and improve determination sensitivity. The method comprises the following steps: accurately shifting 1.00 mu g / mL of freshly prepared phenol-standard solution or a certain amount of to-be-determined water sample subjected to predistillation into a 50mL colorimetric tube; adding water to a scale; adding 0.50 mL of ammoniacal buffer solution and fully mixing the materials; adding 0.40 mL of 1 percent Tween-80 solution and mixing the materials well; adding 1.50 mL of 2 percent 4-amino-antipyrine solution and fully mixing the materials for 2 minutes; adding 1.00 mL of 8 percent potassium ferricyanide solution, fully mixing the materials for 1 minute and keeping the mixture stand for 10 minutes; and then determining the absorbance value of the mixture. A colored compound solution prepared in the invention is stable for at least 2 hours, thus the stability of the colored compound solution is greatly enhanced than that in the prior method before improvement, and the colored compound solution is obviously lower in blank absorbance value and higher in sensitivity, and has detection limit lower than that of the national standard method. The method has the advantage of determining the volatile phenol in tap water samples, along with high recovery rate and accurate results.

The subject of the present invention is to provide a method for producing a silica gel supporting a derivatizing agent for a carbonyl compound that hardly collects carbonyl compounds during production thereof, and a silica gel supporting a derivatizing agent for a carbonyl compound produced by said production method, in order to lower a blank value in measurement of carbonyl compounds. The present invention also relates to a method for producing a silica gel supporting a derivatizing agent for a carbonyl compound characterized by bringing an acid-supported silica gel into contact with an organic solvent containing the derivatizing agent for a carbonyl compound, a silica gel filler supporting a derivatizing agent for a carbonyl compound comprising the silica gel supporting the derivatizing agent for a carbonyl compound produced by the above production method, a method for producing a silica gel supporting a derivatizing agent for a carbonyl compound characterized by treating in advance a silica gel having a cation-exchange group with the derivatizing agent for a carbonyl compound and then bringing it into contact with an organic solvent containing the derivatizing agent for a carbonyl compound, and the like.

The invention provides a method of determining the content of an arsenic element in a coal-containing sample. The method comprises the following steps: S1, preparing a solution to be detected for the coal-containing sample, wherein the solution to be detected contains the arsenic element; S2, determining the arsenic element in the solution to be detected by using hydride generation-atomic fluorescence spectrometry to obtain a detection value of arsenic atomic fluorescence intensity; S3, comparing the detection value with a calibration curve of the arsenic element to obtain the content of the arsenic element in the solution to be detected so as to further obtain the content of the arsenic element in the coal-containing sample, wherein in the hydride generation-atomic fluorescence spectrometry, working parameters of an atomic fluorescence spectrometer are as follows: the lamp current is 60 to 65mA; the negative high voltage is 280 to 290V; the height of an atomizer is 7.0 to 7.1mm; the temperature of the atomizer is 200 to 220 DEG C, and the carrier gas flow is 800 to 815mL.min<-1>. Test parameters and the addition amount of a reagent are adjusted, thereby improving the accuracy and the precision of the method.

The implementation mode in the invention provides a purity detecting method and a device for polysilicon, which belongs to the fields of chemical industry and solar energy. The method comprises the following steps: after evenly mixing silicon powder, washing with secondary deionized water, and drying to constant weight; putting the dried silicon powder on a Teflon tray, adding water to moisturizethe sample, and adding a polyol solution; putting the Teflon tray on a Teflon container, putting the Teflon container in a seal body, adding HF and HNO3 into the lower part of the seal body, sealing the seal body, and heating to 110-120 DEG C; and after the silicon powder is completely dissolved and volatilized to the dry state, adding HNO3 to dissolve residues, transferring to a plastic volumetric flask, and measuring the content of impurity elements after the volume becomes constant. The specific implementation mode in the invention also provides a special device for realizing the purity detecting method for polysilicon. The method and the device have the advantage of high detection accuracy.

The invention discloses a sample rapid digestion method for detecting radionuclide. The method comprises the following steps: (1) weighing a sample, and placing the sample in a microwave digestion tank; (2) adding a digestion solution to the sample, and carrying out microwave digestion in a microwave digestion apparatus; (3) determining the volume of a sample solution after microwave digestion obtained in step (2) to obtain a sample liquid to be tested. In a microwave digestion procedure, the power is 500-800 W, the temperature is 35-130 DEG C, and the reaction time is 25-200 min. According tothe sample rapid digestion method for detecting the radionuclide, the heating is fast, the temperature rise is high, the digestion capacity is strong, the volume of sample digestion is large, and thedigestion time is greatly shortened; the acid solvent consumption is less, and the blank value is low; the sample loss is avoided, and the accuracy and precision of the analysis is improved; the operation is simple, fast, accurate and efficient; the environmental pollution is small, and the working environment is improved; the consumption of electricity is effectively saved, the analysis cost isreduced, and green environmental protection is achieved.

The invention relates to immunological assay reagents and assay method. Immunological assay reagents comprise a composition containing a conjugate composed of an antigen or an antibody against the subject to be assayed and biotin bonded thereto and another composition containing avidin-binding particles, wherein biotin is bonded to the antigen or antibody in the above-described conjugate in such an amount that it would not undergo agglutination together with the above-described avidin-binding particles in the absence of the subject to be assayed; and an immunological assay method which comprises bringing a sample to be assayed into contact with a conjugate composed of an antigen or an antibody against the subject to be assayed and biotin bonded thereto (provided that biotin is bonded to the antigen or antibody in such an amount that it would not undergo agglutination together with the above-described avidin-binding particles in the absence of the subject to be assayed) and avidin-binding particles, and then evaluating the extent of the agglutination caused by the immune complex formed by the subject to be assayed and the conjugate and the avidin-binding particles. By using the above immunological assay reagent and the immunological assay method, a subject to be assayed can be accurately assayed without resort to a procedure of carrying an antibody or an antigen on latex particles (i.e., being free from the autoagglutination of latex particles), thereby achieving a reactivity comparable or even superior to those obtained by the conventional sensitized latex method.

A method for determination of calcium in a sample derived from a living body, by the reaction of calcium in the sample with Chlorophosphonazo-III or a compound analogous thereto in the presence of vanadate ions, followed by determination of calcium in the sample on the basis of an optical change caused by the reaction product, is excellent in various respects as follows: it is free from the problem of absorption of carbonic acid gas caused by a high pH; it is free from the problem of use of a toxic reagent containing arsenic; it makes it possible to subject a large number of samples to determination in a short time because it can be applied to an autoanalyzer; and it permits determination in a wide range because of low sample blank values.

The invention provides a method for measuring the content of free carbon in molybdenum carbide. The method comprises the following steps: (1) adding molybdenum carbide powder into nitro-hydrochloric acid and stirring to dissolve molybdenum carbide in nitro-hydrochloric acid and allowing free carbon to disperse in an undissolved state in nitro-hydrochloric acid, the mass and unit of the molybdenum carbide powder being m0 and g respectively; (2) performing first drying treatment on filter paper, the mass and unit of the filter paper subjected to first drying treatment being m1 and g respectively; the filter paper being binder-free glass fiber filter paper; (3) performing filtration treatment on nitro-hydrochloric acid using filter paper, performing secondary drying treatment after washing with deionized water, and the mass and unit of the filter paper subjected to secondary drying treatment being m2 and g; (4) calculating the mass percentage content x of free carbon in the molybdenum carbide powder. The content of free carbon is detected and analyzed using nitro-hydrochloric acid and binder-free glass fiber filter paper. The design is reasonable, the operation is convenient and easy, the detection error is less, and the result accuracy is high.

The invention discloses a method for detecting the diboron trioxide content in camsellite, which comprises the following steps: processing and washing a glass ware used in detection by acid; placing a camsellite test material into a cleaned heating container provided with a backflow condensing pipe to carry out a blank test along with the test material; adding hydrochloric acid, heating and dissolving the test material at low temperature on a low-temperature heater till the test material is completely dissolved; collecting test material solution into a volumetric bottle to be fixed to certain volume; dissolving a proper amount of high-purity iron in the same acid medium, adopting 50 percent of equivalent iron bases as a base and matching calibration solution containing more than 4 percent of sample boron in mass to prepare a calibration curve; directly carrying out the spectral intensity measurement of a boron element in the test material solution, blank solution and the calibration curve on an electric inductive coupling plasma emission spectrometer by adopting a boron analysis spectral line which is not influenced by iron base content and calculating the mass percentage of the boron element. The method has simple operation step and high analysis result precision and accuracy.

An immunological analyzing reagent comprising a composition containing a biotin-conjugated antigen or antibody against a substance to be analyzed, and a composition containing an avidin-conjugated microparticle, wherein the biotin-conjugated antigen or antibody contains an amount of biotin which does not substantially agglutinate with the avidin-conjugated microparticle in the absence of the substance to be analyzed, is disclosed. Further, an immunological analyzing method comprising the steps of: bringing into contact a sample, a biotin-conjugated antigen or antibody against a substance to be analyzed, and an avidin-conjugated microparticle, the biotin-conjugated antigen or antibody containing an amount of biotin which does not agglutinate with the avidin-conjugated microparticle in the absence of the substance to be analyzed; and detecting the degree of aggregation between the avidin-conjugated microparticle, and an immunocomplex formed from the substance to be analyzed and the biotin-conjugated antigen or antibody, is disclosed. According to the immunological analyzing reagent and analyzing method, a procedure in which an antibody or antigen is carried on a latex particle is not necessary; self-aggregation of latex particles does not occur; a precise measurement of the substance to be analyzed may be carried out; and an excellent reactivity the same as or superior to that obtained by the conventional sensitized latex method may be obtained.

The implementation mode in the invention provides a purity detecting method and a device for polysilicon, which belongs to the fields of chemical industry and solar energy. The method comprises the following steps: after evenly mixing silicon powder, washing with secondary deionized water, and drying to constant weight; putting the dried silicon powder on a Teflon tray, adding water to moisturizethe sample, and adding a polyol solution; putting the Teflon tray on a Teflon container, putting the Teflon container in a seal body, adding HF and HNO3 into the lower part of the seal body, sealing the seal body, and heating to 110-120 DEG C; and after the silicon powder is completely dissolved and volatilized to the dry state, adding HNO3 to dissolve residues, transferring to a plastic volumetric flask, and measuring the content of impurity elements after the volume becomes constant. The specific implementation mode in the invention also provides a special device for realizing the purity detecting method for polysilicon. The method and the device have the advantage of high detection accuracy.

The invention discloses a method for leaching and measuring molybdenum metal in a nickel-molybdenum ore. The nickel-molybdenum ore is treated by a roasting-alkaline leaching method, and a three-factor and three-level test is executed by an L9(43) orthogonal design, so that extraction conditions for the molybdenum content of the nickel-molybdenum ore are optimized; leaching liquid under optimal conditions is centrifugally filtered and then is diluted and quantified; the content of molybdenum is measured by an atomic emission spectrometer; a result shows that the following factors which affect the extraction rate of the molybdenum content of the nickel-molybdenum ore mainly comprise the concentration of sodium hydroxide, the roasting time and the roasting temperature in sequence; under the optimal conditions of leaching molybdenum through sodium hydroxide, the roasting time is 2.5h, the roasting temperature is 500 DEG C, and the concentration of sodium hydroxide is 40 percent. Under the same atomic emission spectroscopy optimized conditions, a marking recycling experiment is performed on a sample. The recycling rate of elements measured by the method is 97.2-102.3 percent, so that the method is high in accuracy. The relative standard deflection is 0.92-1.24 percent, so that the method is high in precision. Therefore, the method can be used for reliably analyzing the molybdenum content of the nickel-molybdenum ore.

An analysis method of carbon element in Mo1 pure molybdenum. The invention relates to the analysis method of carbon element in metal materials, and aims to solve technical problems of high deviation and low accurate degree in an analysis method of the carbon element in Mo1 pure molybdenum in the prior art. The analysis method includes following steps: (1) switching-on and pre-heating a carbon and sulfur analyzer for analyzing carbon elements through an infrared absorption method ; (2) burning an infrared ultralow carbon and sulfur crucible; (3) cooling the burned crucible in a dryer; (4) when the carbon and sulfur analyzer is pre-heated, weighing the Mo1 pure molybdenum, inputting weight values, and adding iron chip and a tungsten-tin flux; and (5) performing measurement according to the analytic methods of the instrument to obtain an analytic result, thereby completing the analysis of the carbon element in the Mo1 pure molybdenum. The analysis method is significantly reduced in deviation and is greatly increased in accuracy. The analysis method is applied in the field of analysis of the carbon element in metal materials.

The invention discloses a sampling membrane and a sampler capable of enriching heavy metals in ambient air and an application method of the sampler. The sampling membrane comprises a nanometer fiber membrane and an air-permeable supporting padding arranged below the nanometer fiber membrane. The sampler comprises the sampling membrane and a sampling clamp; the sampling clamp is composed of an upper cone and a lower cylinder, wherein the upper surface of the cone is horizontal, the cylinder is composed of an upper cylinder and a rotary lower cylinder, the side surfaces of the upper cylinder and the lower cylinder are provided with uniformly distributed vertical ridges, the vertical ridges on the upper cylinder and the lower cylinder are aligned by rotating the lower cylinder, so fixation of the sampling membrane on the horizontal surface of the sampling clamp is realized. After heavy metals in air are acquired by using the sampler, a filter membrane is taken out and put into a centrifuge tube filled with a buffer solution, a solution is used for desorption of the heavy metals on the filter membrane, and after desorption, the solution is determined. According to the invention, detection sensitivity can be substantially improved, pre-treatment of a sample is easy and feasible, and nanometer fiber filter membranes with different functions are used for different detection objects, thereby improving absorption and acquisition efficiency.

The invention relates to a safe and efficient method for determining aluminum in food, which comprises the following steps: (1) weighing a proper amount of sample, and carbonizing by using a resistance furnace; (2) placing the carbonized sample in a muffle furnace for ashing; and (3) taking out the ash, cooling, dissolving with 1% sulfuric acid, and transferring into a 50mL colorimetric tube to obtain a to-be-detected solution. According to the safe and efficient method for determining aluminum in food, no reagent is added basically, so that the blank value is low; the ash content volume of most food after burning is small, so that more samples can be treated, detected components can be enriched, and the detection limit is reduced; organic matters are thoroughly decomposed and the operation is simple.

The invention discloses a method for detecting six phthalates in drinking water through liquid chromatography-mass spectrometry, and belongs to the technical field of drinking water detection. The method comprises the following steps: (1) additionally arranging a protection column; (2) measuring conditions and a mode; (3) establishing a standard working curve; (4) detecting to-be-detected drinking water. According to the detection method, a sample is not required to be pretreated and can be directly fed, so that the six phthalates (DMP (Dimethyl Phthalate), DEP (Diethyl Phthalate), DBP (Dibutyl Phthalate), BBP (Benzyl Butyl Phthalate), DEHP (Di 2-Ethyl Hexyl Phthalate) and DNOP (Di N Octyl Phthalate)) in the drinking water are qualitatively and quantitatively analyzed at high speed; the method has the advantages of easiness and convenience in operation, less sampling quantity, low cost, good reproducibility, high stability and the like, is not only suitable for daily environment monitoring and is also suitable for quick screening of pollutants in emergency accidents.

The invention discloses a sample processing method for detecting boron in industrial silicon with graphite furnace atomic absorption spectrometry. The method comprises the following steps: weighing proper sample silicon powder; selecting proper acid to digest and dissolve the sample; heating to volatilize the silicon, and separating the residue; and filtering to obtain a clear solution and adding Zr-Ba serving as a proper matrix modifier to suppress the interference of a matrix. The method disclosed by the invention can be used for increasing the measurement sensitivity of the graphite furnace atomic absorption spectrometry and improving precision, is high in measurement speed, small in interference, high in accuracy and low in measurement cost, and is especially suitable for the quality detection in an industrial silicon production enterprise.

The invention relates to a method for detecting elemental phosphorus content in industrial wastewater. The method for detecting the elemental phosphorus content in the industrial wastewater comprisesthe steps that the industrial wastewater containing elemental phosphorus is extracted with an organic solvent (benzene), and the elemental phosphorus is collected in extract liquor (benzene); and an appropriate amount of the extract liquor is sucked, a fixed amount of anhydrous methanol and a small amount of silver nitrate are added, the precipitated silver is evenly distributed in a benzene-methanol-water system, and the elemental phosphorus content in the wastewater is determined by spectrophotometer colorimetry. A extraction-spectrophotometry method is adopted to determine the elemental phosphorus content in the industrial wastewater, and the method for detecting the elemental phosphorus content in the industrial wastewater is simple to operate and relatively short in time; a spectrophotometer is used for detecting, a blank value is small, and the detection accuracy can reach 0.01 ppm, so that the method for detecting the elemental phosphorus content in the industrial wastewater ismore conducive to measuring the low-content element phosphorus. An adding standard recovery experiment verifies that the recovery rate is 97% or above, and the experimental result is accurate and reliable.

A method for detecting cadmium content in cigarette used tipping paper is characterized in that the method can quickly and accurately detect the cadmium content in the cigarette used tipping paper by the following steps: adopting mixed acid to carry out microwave digestion for a sample, removing the acid and fixing volume, conducting detection with a graphite furnace atomic absorption spectrophotometer, etc. The method overcomes the shortcoming of the prior art in processing the sample. Compared with the traditional electric heating plate digestion manner, the microwave digestion manner can reduce the usage of samples and strong acid, improve digestion ability, cause less loss to elements to be detected in the sample and less damage to an operator, and facilitate operation. The digestion system of compound acid is completely applicable to the special material of the cigarette used tipping paper. The acid removing process is quick and easy, and a matrix modifier is adopted to eliminateinterference. After being detected by optimal heating programs, ashing temperature and atomization temperature related to atomic absorption spectrometry, the special material of the cigarette used tipping paper is recovered with high rate, and detected with accurate result. The working efficiency and the economic benefits are significantly improved.