121 results about "Graphite furnace atomic absorption" patented technology

The invention discloses a Fe3O4@SiO2 composite material adsorbent preparation method and application. The method comprises the following steps of: synthesizing ferroferric oxide magnetic micro-spheres by using a chemical co-precipitation method; wrapping silicon dioxide on the surfaces of the ferroferric oxide magnetic micro-spheres by using a sol-gel method; and fixing xanthan gum molecules on the surfaces of the magnetic micro-spheres in a functionalized way to prepare an adsorbent. The adsorbent has large specific surface area under nanoscale, high magnetic separation capacity and good stability due to the wrapped silicon dioxide shell layer, rich active adsorption sites are introduced by the xanthan gum molecules in the functionalized way; the Pb adsorption efficiency is over 90 percent. The adsorbent enriches and separates Pb-containing artificial simulate seawater and is subsequently combined with a graphite furnace atomic absorption spectrometry to measure total lead concentration, so that interference of salinity ions in the background of a seawater sample can be effectively avoided, and a standard curve is satisfactory; the lead concentration in the actual seawater is correspondingly tested, and the recovery rate reaches 85.71 percent.

A method for detecting cadmium content in cigarette used tipping paper is characterized in that the method can quickly and accurately detect the chromium 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 small 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 of digesting, settling and separating tungsten-based samples and a detection method for tungsten-based samples. The method of digesting, settling and separating tungsten-based samples comprises the following steps: putting a tungsten-based sample in a container, adding water and nitric acid into the container, keeping the container airtight, carrying out microwavedigestion and settlement-separation on the sample under gradient temperatures, and restarting microwave for rinsing and deposition after the temperature of the solution decreases and is close to the boiling point of water so as to obtain a sample solution for detection and precipitates of tungstic acid. The detection method for tungsten-based samples in the invention is to analyze the digested sample solution with at least one analytical method selected from the group consisting of inductively coupled plasma mass spectrometry, inductively coupled plasma atomic emission spectrometry, flame atomic absorption spectrometry, graphite oven atomic absorption spectrometry and spectrophotometry so as to obtain the content of elements in the tungsten-based sample.

The invention discloses a method for clearing and detecting vanadic oxide which includes steps as follows: taking vanadic oxide to a container, adding nitric acid to the container, processing pre-action under the normal temperature, then closing the container, processing microwave clearing. The detecting method includes steps as follows: using one or many methods of an inductively coupled plasma mass spectrometry, an inductively coupled plasma atomic emission spectrometry, a flame atomic absorption spectrometry and a graphite furnace atomic absorption spectrometry for analyzing the cleared vanadic oxide, accordingly, obtaining elementary content of vanadic oxide sample.

The invention discloses a method for determining boron content in rubber. The method employs a graphite furnace atomic absorption spectrometry method for determination and calculation of boron content in rubber. The method comprises steps of: conducting pretreatment on a rubber sample; conducting high-temperature ashing by a muffle furnace; adding a mixed acid of hydrofluoric acid and concentrated sulfuric acid in the ash; digesting, drying and placing the ash in the muffle furnace; calcining at 800 DEG C; dissolving the ash with hydrochloric acid to gain a transparent sample solution, and conducting a blank test with the sample; preparing a boron standard work solution above 4 point by using a boron standard stock solution; adding a matrix modifier Ca (NO3) 2 with a same concentration into the sample solution, the blank solution and the standard work solution, and adding high purity water for constant volume; optimizing test conditions of the graphite furnace atomic absorption spectrometry, measuring boron absorbance of the sample solution, the blank solution and the standard solution, and drawing a standard working curve to obtain boron concentration in the sample solution; and calculating the content (in percentage) of boron in the rubber sample. The determination method has advantages of results with high precision and accuracy.

The invention discloses a digestion method of detection of heavy metals in soil. The digestion method is characterized by comprising the following steps: only adding a small amount of nitric acid and a small amount of hydrofluoric acid into a sample; after leaving the mixture to stand overnight, digesting on a graphite digestion device at a certain temperature to completely digest the soil sample; detecting with graphite furnace atomic absorption spectrometry or inductively coupled plasma optical emission spectrometry. The digestion method is accurate and reliable, and meets the detection demands.

The invention provides a liquid adsorbent and a method for controlling arsenic pollution of lake water, which relates to large-scale treatment of arsenic-polluted water. The adsorbent is reserve liquid formed by compounding iron salts FeCl3 or Fe2(SO4)3 or adding an appropriate amount of aluminum salts AlCl3 or Al2(SO4)3 with tap water or deionized water, and the mass concentration of the adsorbent is 100 to 600 g/L. The adsorbent in use is diluted by 10 to 30 times and then sprayed on the arsenic-polluted water. The adsorbent has the advantages of safety, low price, high arsenic removal efficiency and easy operation. A Yangzonghai arsenic-polluted water sample treated with the invention is detected through graphite furnace atomic absorption spectrometry and atomic fluorescence spectrometry, and detection results show that the arsenic removal rate of the invention can be greater than 92.7 percent, and the invention can reduce arsenic concentration from 0.110-0.130 mg/L to 0.003-0.008 mg/L which is lower than 0.050 mg/L specified by the national drinking water health standard (GB5749-2006) and 0.010 mg/L specified by the WHO drinking water quality standard.

The invention discloses a method for testing arsenic content in tobaccos and tobacco products, which comprises adopting nitric acid-hydrogen peroxide to digest through microwaves, then taking chlorine lawrencium acid ammonium and citric acid as chemical promoting agents, using Zeeman to deduct backgrounds, and adopting graphite furnace atomic absorption spectrometry to test the arsenic content in tobacco samples. Results shows that the detecting limit of the arsenic content is 0.28 um g/L, recovery ratio is between 92.0%-102.0%, and RSD is<3.0%. Agent species and quantity which are used for digesting are decreased greatly, analyzing time is shortened greatly, the invention is simple, rapid, applicable for the rapid arsenic content tests of tobacco samples in batches, and has good technique extending value.

The invention provides a method for simultaneously determining trace gold, silver and palladium in a geochemical sample. The method comprises the following steps: firstly, digesting the geochemical sample by using 1:1 chloroazotic acid in a constant-temperature boiled water bath in a sealed manner; secondly, selectively enriching the trace gold, silver and palladium by using diphenylthiourea loaded polyurethane foam, and separating other interference elements; and finally, drawing a standard curve of Au197, Ag107 and Pd105 by adopting an inductively coupled plasma source mass spectrometer through a standard curve method, and simultaneously determining the trace gold, silver and palladium in the sample. According to the method provided by the invention, the problem that other main interference elements with the abundance of geochemical elements, which is hundreds, even thousands of times of that of the silver and the palladium, have interference on mass spectrums of the silver and the palladium is solved; and compared with a traditional emission spectrum and graphite furnace atomic absorption spectrometry, the sampling amount in analysis of the silver in the geochemical sample is increased by dozens of times, so that the influences caused by gold grain effect of the geochemical silver are effectively overcome.

The invention discloses a method for measuring the content of arsenic in edible oil by utilizing a super-microwave digestion graphite furnace atomic absorption spectrometry. The method disclosed by the invention comprises the following steps: performing super-microwave digestion on an edible oil sample by adopting a transparent and stable quartz tube, and measuring the content of the arsenic in the edible oil by utilizing the graphite furnace atomic absorption spectrometry. According to the method, a super-microwave technology is applied to measuring the trace arsenic in the edible oil, the operation is safe and easy, the digestion capacity is high, the edible oil samples can be simply and efficiently digested, the target analyte loss and pollution caused by the transfer process can be effectively eliminated, potassium borohydride and other substances with high toxicity are not needed, and the graphite furnace atomic absorption spectrometry is further combined to be applied to measuring the trace arsenic in the edible oil. According to the method disclosed by the invention, the linearity range ranges from 0 to 40ng/mL, the quantification limit is 0.033mg/kg, and the recovery rate is 86.8-101.4 percent. The operation is easy, accurate, rapid and sensitive, the content of the arsenic in the edible oil can be accurately measured, and the body health of consumers can be effectively guaranteed.

The invention relates to a method for testing chromium in milk and milk products, which comprises the following steps: firstly, preparing a plurality of chromium standard solution with different concentrations, respectively testing the chromium standard solution, drawing the standard curve diagram between the content of chromium and the testing result according to the data which are measured, secondly, testing samples with the same method, and getting a testing result, thirdly, comparing the testing result in the step two with the stand curve diagram, and getting the content of chromium in the samples. The check out test set which is used in testing is an atomic absorption spectrophotometer of a graphite oven iron. The samples are tested after ashing and digesting by 5% nitric acid, the ashing temperature is 800 DEG C, and the atomization temperature is 2600 DEG C. The correlation coefficient reaches more than 0.999 in 0.0-10.0ng/ml linear range, and the coefficient of recovery is 88.1%-96.9%. Matrix modifier is not needed to be added in the method. The utility model has the advantages of high sensitiveness, little reagent dosage, little disturbance and the like, which is simple and fast.

The invention discloses a determination method of arsenic content in hot melt glue. The method is characterized in that the arsenic content in hot melt glue is determined by adopting the steps of sample predigestion, mixed acid microwave digestion, cast acid constant volume, graphite furnace atomic absorption spectrometer and the like, the arsenic content in hot melt glue can be rapidly and accurately detected. The determination method of arsenic content in hot melt glue provided by the invention overcomes the defects of the sample processing method in the prior art, compared with the traditional digestion mode of the electric hot plate, the using quantity of samples and strong acid can be reduced by adopting a microwave digestion mode, the digestion capability is improved, the loss of the sample to-be-determined element is less, the damage to operating personnel is tiny, and the method is easy to operate; by the method, the cast acid process is rapid and simple, and interference is eliminated by adopting a base body improving agent; and aiming at the material characteristics of hot melt glue, after by adopting the determination of the warming procedure, the ashing temperature and atomic temperature relative to the optimized atomic absorption spectrum method, the recycling rate is high, and the determination result is accurate.

The invention belongs to the chemical detection analysis field and in particular relates to a technology for rapidly determining lead and chromium in dairy products by use of a microwave digestion-graphite furnace atomic absorption spectrometry. The method comprises the following steps: (1) preprocessing a sample; (2) preparing lead and chromium standard curve series solutions; (3) drawing lead and chromium standard curves; and (4) measuring the sample. Compared with the prior art, the method has the beneficial effects that the sample preprocessing time is short and is only 2.4h, the operation is simple, the harm to laboratory technicians can be reduced to the maximum extent due to use of microwave digestion, the environment is friendly, the whole microwave digestion process of the sample is performed in a closed environment, a small amount of target detection substances are volatized, the contamination of external substances is avoided, the detection result has high accuracy and good repeatability, lead and chromium in the dairy product can be measured simultaneously, and the method is suitable for the batch processing and measurement of samples, is suitable for determining the contents of lead and chromium in various samples such as raw milk, sterilized milk, modified milk, milk powder, fermented milk and the like, and has wide application range.

The invention discloses a method for determining the content of lead in hot melt adhesive. The method is characterized in that the content of the lead in the hot melt adhesive can be detected quickly and accurately by measurement through the steps of sample pre-digestion, mixed acid microwave digestion, acid removing and volume metering, standard blank solution preparation, atomic absorption spectroscopy determination of a graphite furnace and the like. According to the method disclosed by the invention, the defects in a sample treatment method in the prior art are overcome; compared with a digestion mode of a traditional electric hot plate, the method disclosed by the invention has the characteristics that due to the adoption of a microwave digestion mode, the usage amounts of the sample and strong acid can be reduced and the digestion capacity is improved; and in addition, the loss of elements of the sample to be determined is less, the harm to an operator is small and easy operation is realized. According to the method, the acid removing process is quick and simple; and the interference is eliminated by adopting a matrix modifier. For the characteristics of hot melt adhesive materials, after relevant temperature-rise programs, ashing temperature and atomization temperature of the optimized atomic absorption spectroscopy are used for determining, high recovery rate and accurate measurement result are obtained.

The invention discloses a new analytical reagent for detecting trace lead, which has the chemical structure represented by the general formula (I). The analytical reagent is synthesized by the following two steps of reaction: firstly, using sulfanilic acid to prepare diazonium salt; then, coupling with 8-azly quinaldine to obtain the analytical reagent. The invention provides a new method for detecting trace lead based on the newly synthesized analytical reagent, and the method is applied to analysis tests in the tobacco industry. The defect of relatively low sensitivity of absorption photometry is overcome, so that the common photometry can be used for detecting mug/g level lead. The detection results of the method are consistent with the results of the graphite furnace atomic absorptionmethod.

The invention relates to a method for measuring the graphite oven atomic absorption spectrum of an arsenic element in steel, which comprises the following steps: setting the atomization condition of a graphite oven atomic absorption spectrophotometer and constructing an analytical standard curve, wherein the atomization working condition of the graphite oven atomic absorption spectrophotometer is as follows: in the drying condition of a steel sample to be measured, the temperature is firstly raised from the room temperature to the temperature of 100+/-2 DEG C, is kept for several seconds, then is raised to the temperature of 120-150 DEG C within several seconds and is kept for several seconds, and the flow rate of carrier gas is 250+/-10mL/min; in the incineration condition of the steel sample to be measured, the temperature is raised to the temperature of 1200+/-10 DEG C within several seconds and is kept for several seconds, and the flow rate of the carrier gas is 250+/-10mL/min; in the atomization condition of the steel sample to be measured, the temperature is instantaneously raised to the temperature of 2300+/-10 DEG C and is kept for several seconds, and the carrier gas is closed; the idle-burning washing temperature is 2450+/-10 DEG C, the slope time is several seconds and is kept for several seconds, and the flow rate of the carrier gas is 250+/-10mL/min; the current of an electrodeless discharge lamp is 350-400mA, and the wavelength is 180-200nm; the slit width is 0.5-1nm; and the method also comprises the step of carrying out coating treatment on a graphite pipe of the graphite oven atomic absorption spectrophotometer.

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 discloses a sample preparation method and detecting method for detecting impurities in a titanyl sulfate solution. According to the invention, the sample preparation method for detecting impurities in the titanyl sulfate solution comprises the following steps: diluting the titanyl sulfate solution by using a mixed solution of ethanol and water so as obtain the sample used for detecting the impurities in the titanyl sulfate solution. According to the invention, the method for detecting the impurities in the titanyl sulfate solution comprises the following steps: preparing the sample by using the sample preparation method, and detecting the content of at least one element of Nb, Zr, Pb, Sn, V, Al, Mg, Mn, Mo, Ni, P and Zn in the sample by using at least one method of inductively coupled plasma atomic emission spectrometry, inductively coupled plasma mass spectrometry, flame atomic absorption spectrometry and graphite furnace atomic absorption spectrometry.

The invention discloses a method for determining cadmium and trace lead in an iron ore. The method comprises the following steps: digesting an iron ore sample by virtue of a microwave digestion apparatus, and determining a test solution by virtue of an atomic absorption spectrometer of a graphite furnace, wherein the microwave digestion comprises the following processes: putting dried iron ore into a polytetrafluoroethylene digestion tank, wetting with deionized water, and adding nitromurlatic acid; after sharp reaction is ended to obtain a mixture, putting the mixture into a furnace cavity of the microwave digestion apparatus, setting the digestion temperature to 190 DEG C, the heating time to 20 minutes, and digestion keeping time to 20 minutes; after the digestion is ended, cooling to a room temperature, taking out the digestion tank, and taking out the sample in the tank; and adding water to be in constant volume, so as to obtain a to-be-tested solution of the sample. According to the method, the sample can be completely digested by virtue of a microwave digestion method; the detection result is consistent with those of other methods under the condition that a base modifier is not added; and the method has the advantages of being simple, rapid, and accurate, and is suitable for determination of the cadmium and the trace lead in the iron ore.

The invention discloses a micro-fluidic chip-based capillary electrophoresis and graphite furnace atomic absorption online coupling interface device, which comprises an external capillary connected with a separation channel outlet of a micro-fluidic chip, wherein the other end of the eternal capillary is inserted into a thermo-spray tube; an air carrying tube and a circulating water cooling sleeve are sequentially sleeved outside the thermo-spray tube; a spray nozzle of the thermo-spray tube is horizontally inserted into a hollow graphite cap fixed in front of a graphite tube feeding hole; and the thermo-spray tube, the air carrying tube and the circulating water cooling sleeve are metal conductive bodies and are connected with the cathode of a power supply of the micro-fluidic chip so as to form a stable electric circuit for chip electrophoresis separation. In the interface device, through the design of a flow path of a tube-in-tube type sleeve flow at an interface, a separated species to be tested is vaporized and is continuously and stably introduced into a graphite tube at a constant speed in a thermo-spray way, which ensures the timely delivery of the species in a separated state. The interface simultaneously meets the detection requirements of micro-fluidic chip-based capillary electrophoresis separation and graphite furnace atomic absorption spectroscopy.

The invention relates to a method for measuring the contents of strontium and aluminum in a strontium chloride injection by graphite furnace atomic absorption spectrometry. The method comprises the following steps of: precisely absorbing a standard solution and diluting; preparing the diluted solution to the standard solution; measuring the standard solution by using the atomic absorption spectrometry to obtain a standard curve; measuring the strontium chloride injection by using the atomic absorption spectrometry; and comparing the standard curve to obtain the contents of the strontium and the aluminum in the strontium chloride injection. Compared with the prior art, the method disclosed by the invention has the characteristics that the input and operation cost is low and expenses consumed by an ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) are 4 times of the expenses GFAAS (Graphite Furnace Atomic Absorption Spectrometry); and the method has the advantages of simplicity in operation, low detection limit and the like, and is mature in the analysis method.

The invention relates to a method for measuring lead content in soybean sauce through microwave digestion-graphite furnace atomic absorption. The method comprises the following steps: weighing a defined amount of sample and putting into a polytetrafluoroethylene digestion tank; adding nitric acid and hydrogen peroxide; performing digestion pretreatment in a microwave digestion instrument; respectively taking the digested sample, palladium nitrate in mass percent of 10% and ammonium dihydrogen phosphate in mass percent of 10% and jointly injecting into a pyrolytic coating graphite tube for measuring. According to the method provided by the invention, the influence of soybean sauce substrate on lead measurement can be effectively reduced, the stability and precision of the method can be increased and the test process is simple, quick, sensitive and accurate. The method is suitable for the measurement for the lead content in soybean sauce and daily food, such as, pickle, salt, vegetable and milk powder.

The invention relates to a pre-treatment and quantitative analysis method for rapid determination of the content of the cadmium element in rice. The method comprises the following steps (1) crushing rice into powder; (2) preparing an agar solution with a concentration of 0.8 to 1.5 gL; (3) weighing a plurality of parts of rice powder as parallel samples, respectively subjecting the parallel samples to suspension and volume fixation with the agar solution prepared in the step (2), carrying out dilution with dilute nitric acid so as to obtain to-be-measured sample liquids with rice concentration of 4 to 16 gL and directly diluting the agar solution obtained in the step (2) with dilute nitric acid so as to obtain a blank sample; (4) preparing cadmium standard solutions, determining the absorbance value of each cadmium standard solution by using graphite furnace atomic absorption spectrometry and drafting a cadmium element standard curve; and (5) determining the absorbance values of the to-be-measured sample liquids and the blank sample and calculating cadmium content of the to-be-measured sample liquids. The method provided by the invention is simple and fast, can rapidly detect the content of the cadmium element in rice and has good accuracy and repeatability.

The invention specifically relates to a determination method for trace thallium in high-salt waste water, which belongs to the technical field of heavy metal detection. The determination method for trace thallium in high-salt waste water comprises the following steps: (1) pretreating a waste water sample by using a continuous impurity removal and enrichment method consisting of procedures of extraction, washing, reverse extraction, pH value adjustment of an extraction solution, extraction, washing and reverse extraction; (2) drafting a standard work curve of thallium; (3) detecting the absorbance of the pretreated to-be-detected waste water sample through graphite furnace atomic absorption; and (4) calculating the concentration of the sample according to standard absorbance-concentration relation. According to the invention, extractant used in the method is regenerable and reusable; an added-standard recovery rate reaches 98 to 102%, and a detection limit value is up to 0.1 [mu]g/L, so emission standard detection requirements on thallium in industrial waste water are met; and a blank in determination methods for trace thallium in high-salt waste water is filled in.

The invention relates to the field of cigarette, specifically to a method for detecting the lead content of cigarette paper. The method comprises the steps of: weighing the cigarette paper, adding a digesting agent for microwave digestion to obtain a sample, and detecting the sample by using a graphite furnace atomic absorption spectrometer. The digesting agent employed is a nitric acid-hydrogen peroxide-high-purity water solution, wherein the volume ratio of the nitric acid, the hydrogen peroxide and the high-purity water is 4:2:2. The addition proportion of the cigarette paper and the digesting agent is 0.3g:8ml. Charring and atomization temperatures are 700-780 DEG C and 1900-2050 DEG C, respectively. The method for determining lead in the cigarette paper has the advantages of high sensitivity and good accuracy, and is simple, convenient, rapid and accurate.

The invention discloses a graphite tube which is used for graphite furnace atomic absorption spectrophotometer and a preparation method thereof, wherein, the tube body is prepared by graphite and is provided with an electrode; the tube body except the electrode is covered with a pyrolysis graphite layer which is characterized in that the pyrolysis graphite layer is covered with a layer of metal carbide with high melting point and strong antioxidation ability. The invention has simple preparation method and can prolong the service life of the graphite tube by 30% to 50%. The preparation method in the invention is not only applicable to heating the graphite tube longitudinally, but also applicable to heating the graphite tube transversely.

The invention discloses a matrix modifier for determining heavy metals absorbed by graphite furnace atoms, and a preparing method. The matrix modifier is colloid palladium, and the preparing method of the matrix modifier comprises the following steps of: weighing 0.024g-0.036g of palladium chloride, and placing into a reacting container; converting into H2PdC14.nH2O by using concentrated hydrochloric acid; adding 0.030g of polyvinylpyrrolidone; then, slowly adding 60mL of mixing solution of methanol and water, continuously stirring and uniformly mixing in the adding process, placing the solution into a water bath tank for refluxing by heating for 90 minutes, and then taking out a brown colloid solution which is the target palladium. The novel matrix modifier can achieve high podzolizing temperature, the interference matrix can be effectively removed in the podzolizing stage, and the purpose for reducing or eliminating the interference is achieved. The colloid palladium prepared by the invention has uniform particle distribution, and no obvious aggregation phenomenon.