85results about How to "Simple pre-processing" patented technology

The invention discloses a determination method of an amount of phthalic acid esters. The determination method comprises the following steps: carrying out alkaline hydrolysis on samples in order; acidifying to converse all phthalic acid esters in samples into phthalic acid; extracting by ethyl acetate; drying out and redissolving with methanol; filtering by organic filter membrane to obtain sampleliquids; determining phthalic acid content in the sample liquids by high performance liquid chromatography; carrying out conversion according to a phthalic acid standard substance peak area- mass concentration standard curve and a linear regression equation to calculate out the amount of phthalic acid esters in the samples. The determination method of the amount of phthalic acid esters has advantages of simple pre-treatment, rapidness and high sensitivity, is beneficial for large-scale sample determination and suitable for determination of the amount of phthalic acid ester in oil food, like edible oil, seasoning sauce for instant noodle and convenient rice noodle, and urine biological specimen.

The invention relates to a processing technology of a spinning belt pulley with inner and outer lug bosses, which belongs to the field of manufacturing belt pulleys. The processing technology comprises the following steps of: stamping and performing a blank, reprocessing the performed blank and spinning the reprocessed and performed blank, wherein the reprocessing step of the performed blank comprises the following steps of: cold extruding a formed blank A into a performed blank B with a predetermined size; and rolling and forming the performed blank B by a spinning mode to form the performed blank C with inner and outer lug bosses. Compared with the traditional processing technology, the processing technology of the spinning belt pulley with the inner and outer lug bosses has wide source of raw materials, low cost, high production efficiency and low rejection rate, the spinning mode is used for replacing a stamping mode to produce the blank with the inner and outer lug bosses, products are not easy to deform, the dimensions of the product can achieve higher required precision, and an adopted spinning machine has small erosion, low power consumption and convenient maintenance.

The invention relates to a method for increasing anaerobic fermentation gas yield of energy grasses. According to the method, the energy grasses are subjected to ensiling pretreatment, and lactic acid bacteria and cellulase are added at the same time during ensiling so as to change the fiber structure of the energy grasses and increase the total amount of fermentable dry matters in an ensilage raw material, thus the anaerobic-fermentation methane production efficiency of the energy grasses is increased remarkably. The method for increasing the anaerobic fermentation gas yield of the energy grasses, provided by the invention, is a biological method, ensilage additives are all biological raw materials, and ensiling is also a biological process, so that the gas production efficiency of the energy grasses can be increased remarkably, and secondary pollution can not be caused; the whole process is simple in operation and is safe and reliable, the used raw materials are wide in source and low in cost, the requirements for production sites are low, the industrial large-scale production can be carried out, and the cost is remarkably lower than that of other bioenergy, such as fossil energy, bioethanol, biodiesel and the like, so that the method has market competitiveness.

The invention discloses a method for determining ethylene glycol monomethyl ether, glycol ether, ethylene glycol ether acetate, glycol and diglycol in food wrap paper. The method disclosed by the invention comprises the following steps of: weighing and placing shredded food wrap paper into a container, adding a methanol extraction solution containing internal standard substances into the container, carrying out ultrasonic extraction, filtering extract liquor by virtue of a filter membrane, detecting filtrate by adopting a gas chromatography / mass spectrometer, monitoring in a selected ion mode and quantifying, and obtaining the contents of ethylene glycol monomethyl ether, glycol ether, ethylene glycol ether acetate, glycol and diglycol in the food wrap paper. The method disclosed by the invention has the advantages of simple pre-treatment, easiness in operation, good separating effect, accurate determination, short sample analysis time and high determination sensitivity and can realize accurate batch determination on five components in the food wrap paper at the same time.

A method for rapidly detecting TNT in water based on surface-enhanced Raman spectroscopy relates to a Raman spectroscopy detection method. The method of the invention comprises the following steps: synthesis of gold nanoparticles; molecular modification of TNT; surface-enhanced Raman spectroscopy detection of TNT standard substances; and detection of samples. The pretreatment is simple, instrumentoperation is simple, and the detection can be realized without a professional; the detection time is short, the instrument is convenient, and the on-site rapid detection is convenient; the accuracy is high, the detection cost is low, and the detection limit is low.

The invention relates to an LC-MC method used for determining NNK metabolites in liver microsomes and specifically to an LC-MC method used for analyzing and determining 4-(methyl nitroso)-1-(3-pyridyl)-1-butanone (NNK) metabolites in liver microsomes, which belongs to the field of biochemical analysis. The method provided in the invention mainly comprises the following steps: (1) preparation of an incubation system for liver microsomes; (2) sample treatment; (3) sample analysis and determination of NNK metabolites in the liver microsomes by using the LC-MC method. The invention has the following advantages of simple pre-treatment, a fast analysis speed, good selectivity, high detection sensitivity and capacity of analyzing and comparing the metabolism of NNK in different kinds of liver microsomes, can lay a methodological foundation for further research on in-vivo and in-vitro metabolism of NNK and other nitrosamine compounds and has critical significance.

The invention discloses a detection method of 2-methylimidazole and 4-methylimidazole in baked food. A mixed solution of trichloroacetic acid and methyl alcohol is added to a baked food sample to make protein, colloid and other impurities subside, supersonic extraction is conducted, a solution to be detected is obtained through centrifugation and filtering, a CAPCELL CR (1:4) chromatographic column (5 microns, 2.0 mm*150 mm) is adopted for separation, and the 2-methylimidazole and the 4-methylimidazole are subjected to qualitative and quantitative analysis through an isotope dilution ultra high performance liquid chromatography tandem mass spectrometry method. The method is free of solid phase extraction and other complex sample pre-processing procedures, three types of isomeride of the methylimidazole can be effectively separated, the ion inhibition effect is effectively lowered, sensitivity is improved, and the detection method has the advantages of being low in detection limit and good in accuracy.

The invention discloses a composite silica gel column and a pretreatment method for simultaneously measuring multi-type persistent organic contaminants in sediments and biological samples. The composite silica gel column comprises glass wool, silver silicate silica gel, activated silica gel, alkaline silica gel, activated silica gel, first acid silica gel with the acid content of 40 wt%-50 wt%, second acid silica gel with the acid content of 20 wt%-25 wt%, activated silica gel and anhydrous sodium sulfate sequentially from bottom to top.

The invention discloses a method used for synchronous detection of eight disinfection by-products including four haloacetonitriles. The method comprises following steps: S1, mixed standard solutions of a series of concentrations are prepared; S2, chromatographic conditions are set; S3, a standard curve is drawn; S4, sample collecting and pretreatment are carried out; and S5, samples obtained in S4 are subjected to detection at the chromatographic conditions set in S2, and a measured peak are value is introduced into the standard curve so as to obtain the corresponding concentration via calculation. The method is high in sensitivity, qualitative capacity, and precision; interference peaks are few; and the method can be used for synchronous detection of a plurality of disinfection by-products in water body in practice.

The invention discloses a surface enhanced Raman spectroscopy method for organo-chlorine pesticide residues of fruits and vegetables and belongs to the technical field of detection methods of pesticide residues. The method comprises the following steps: 1, preparing a copper foil substrate; 2, depositing silver nanoparticles on the surface of the copper foil; 3, modifying mercapto on the substrate; 4, performing surface enhanced Raman spectroscopy on organo-chlorine pesticide standard products; and 5, detecting the pesticide residues of the fruits and vegetables. According to the method disclosed by the invention, the sample pretreatment is simple, the detection speed is high, the detection cycle is shortened, the cost is low, and rapid detection of micro / trace pesticides of the fruits andvegetables is realized.

The invention provides a method for calculating a mass concrete water pipe cooling temperature field. The method comprises the following steps of: first, giving an initial temperature field of concrete, and determining whether a cooling water pipe supplies water or not, calculating directly if the cooling water pipe does not supply water, otherwise performing the following steps: calculating on-way water temperature of the cooling water pipe in the concrete, taking a generalized water pipe node as a common node to synthesize an integral matrix according to the traditional method, adding a formed matrix into the integral matrix, and solving to acquire the concrete water pipe cooling temperature field in the next time step. By adopting the method, water pipe information is concealed in a node of an existing unit, so that the pre-processing workload is reduced; a finite element calculation format and a water pipe on-way water temperature calculation formula of the water pipe cooling temperature field are established, no iteration is required in the calculating process, so that the solving speed is ensured, and temperature changes close to the water pipe can be reflected.

The invention discloses a method for rapidly determining melamine in milk and dairy products by liquid chromatography-tandem mass spectrometry (LC-MS / MS). According to the invention, an internal standard is added to a dairy product requiring detection; melamine is extracted by using acetonitrile; a normal-phase chromatographic column is adopted; a solution of acetonitrile and an ammonium acetate buffer salt is adopted as a mobile phase, and melamine is subject to reversed-phase separation; with tandem mass spectrometry, melamine in the milk and dairy products is subject to MRM qualitative and quantitative analysis. With a national standard method, purification is carried out by using an SPE columella, and a final constant volume is 1mL. With the rapid method provided by the invention, a final volume is 25mL. The adopted curve linearity range is 0.25ng*mL<-1> to 5.00ng*mL<-1>. When the value is multiplied 25 times the dilution difference, the value is 6.25mg / kg to 125mg / kg, which reaches and satisfies the requirement of the national standard. With the method, the sensitivity is improved, and the possibility of an overloaded sample is reduced.

The invention relates to a method for determining alkaloid in coffee tincture. The method is characterized in that water is taken as sample diluting solvent, mixed solution of methyl alcohol and 0.1% methanoic acid aqueous solution is taken as a mobile phase, and the high performance liquid chromatography is adopted to simultaneously detect caffeine, trigonelline and nicotinic acid in coffee tincture, wherein a diode array detector is adopted. The method has the key points that the water is taken as the sample diluting solvent and the 0.1% methanoic acid aqueous solution is taken as the mobile phase. The water is taken as the sample diluting solvent, thus pigment in a sample which enters into a chromatographic column is reduced, a chromatographic column is effectively protected, a sample preprocessing solvent is environmentally friendly, and the chromatographic peak shape of alkaloid is not influenced. Compared with pure water taken as the mobile phase, the 0.1% methanoic acid aqueoussolution is taken as the mobile phase, and the chromatographic peak shape can be effectively improved, thus being beneficial to accurate determination of nicotinic acid. The method has the advantagesof simple preprocessing, good repeatability and high recovery rate and can be applicable to analysis of samples on a large scale.

The invention relates to a method for separating and determining pyrazine substances and pyridine substances in saliva, and belongs to the technical field of analytical chemistry. A saliva sample is collected through absorbent cotton, is centrifuged and undergoes solid phase extraction, and the pyrazine substances and pyridine substances in saliva are determined through gas chromatography-mass spectrometry. The method comprises the following steps: 1, collecting the saliva sample by using absorbent cotton, placing the absorbent cotton in a syringe needle cylinder after collection ends, pushing a syringe push rod to carry out extrusion in order to obtain a saliva sample, carrying out high speed centrifuge, and taking the obtained supernatant; 2, adding an internal standard substance to the saliva sample, carrying out solid extraction column enrichment, and eluting the obtained material with a solvent; and 3, concentrating the obtained eluate, re-dissolving the obtained concentrate, allowing the re-dissolved concentrate to go through a millipore filter membrane, determining the filtered solution through gas chromatography-mass spectrometry, making a standard curve, and carrying out internal standard method quantification. The method can be effectively used to determine pyrazine substances and pyridine substances in saliva, and has the advantages of feasibility, low detection limit, good precision, high accuracy and reliability, and promotion application values.

The invention discloses a method used for simultaneous measurement of vanillin, methyl vanillin, and ethyl vanillin in food. According to the method, measurement of vanillin and ethyl vanillin is carried out after conversion of vanillin and ethyl vanillin into propionates via derivatization. The method comprises following steps: solution preparation, standard stock solution preparation, sample solution preparation, gas chromatography-mass spectrometry qualitative analysis, and quantitative determination. The method can be used for simultaneous measurement of vanillin, methyl vanillin, and ethyl vanillin in cereal grains, liquid milk, single cream, plant oil, and infant formula foods; propionic anhydride derivatization is adopted; detection efficiency is high; detection cost is low; and themethod is rapid and simple, is high in efficiency, and is convenient to popularize.

The invention belongs to the technical field of analytic chemistry, and particularly relates to a method for determining the content of chloromethyl methyl ether in automotive materials. The method comprises the following determining steps: (1) cutting a to-be-determined sample into small cubes with sizes of about 2mm*2mm*2mm, and sealing for later use; (2) weighing a certain amount of sample and placing the sample in a headspace bottle, adding acetone, adding toluene-d8 as an internal standard, after fastening the bottle cover down, placing in a headspace sampler; and (3) determining the content of chloromethyl methyl ether in a sample by adopting a gas chromatography-mass spectroscopy meter. According to the method, the content of chloromethyl methyl ether in the automotive materials is determined by adopting the gas chromatography-mass spectroscopy meter, and is quantified by adopting an internal standard method; the method is little in sampling amount, simple in pretreatment operation, and rapid in testing; accurate determination of the content of chloromethyl methyl ether in the automotive materials can be realized, and the detection limit of the method is 100mg / kg.

The invention discloses a lipidomics analysis method for toxoplasma gondii based on high performance liquid chromatography tandem high-resolution mass spectrum and application. The lipidomics analysismethod comprises the following steps: using a chloroform-methyl alcohol-aqueous solution for suspending a to-be-detected toxoplasma gondii sample and then performing ultrasonic disruption; centrifuging extracting solution, performing nitrogen blowing and re-dissolving with methyl alcohol, and then filtering and feeding the sample; using a liquid phase C18 chromatographic column for separating; utilizing mobile phases A and B composed of acetonitrile, isopropanol, ammonium acetate, methyl alcohol and water to elute, and then performing detecting in a full-scan manner respectively under positive and negative ion modes using a QTOF high-resolution mass spectrometer; and screening and identifying the detected data according to the chemical formula of target lipid molecules. The method has theadvantages of sensitivity and accuracy, and being independent of standard compound, and can be efficiently used for lipidomics analysis of the toxoplasma gondii.

The invention discloses a time-resolved fluoroimmunoassay kit for detecting adprin as well as a detecting method of the time-resolved fluoroimmunoassay kit. The time-resolved fluoroimmunoassay kit consists of a porous coating plate, a buffer solution, an adprin standard product, an adprin antibody lyophilized product, a europium-labeled goat-anti-mouse antibody, a washing solution and an enhancement solution. The detecting method of the time-resolved fluoroimmunoassay kit comprises the following steps: (1) immunogen preparation; (2) dox-ova preparation; (3) monoclonal antibody preparation; (4) sample pretreatment and detection. According to the invention, the detection time is short, the average recovery rate is high, the sample pretreatment is simple, spot operation detection is realized, the application is wide, the detection cost is low, and the advantages that the detection specificity is strong, the intra and inter difference is less, the sensitivity is high, the operation is simple and quick, and the kit is particularly suitable for detection of mass samples are achieved.

The invention relates to a method for detecting melamine by ion chromatography. The method comprises the following steps of: pretreating a sample to be detected by using an on-line osmotic membrane method to obtain an extracting solution of the sample; analyzing a peak area of the extracting solution of the sample by using an ion chromatograph, and comparing with a marked calibration curve to obtain the concentration of melamine in the extracting solution, thus obtaining the concentration of the melamine in the sample to be detected, wherein detection conditions of the ion chromatograph are that the sample size is 20 mu L, leacheate is an aqueous solution of sulfuric acid at the concentration of 1.5mmol / L, the flow rate is 0.9mL / min and the detection wavelength of an ultraviolet detector is 240nm. Compared with the prior art, the method has the advantages that: the melamine content in multiple samples can be effectively detected, the whole operation is simple and quick, the detected melamine content is accurate, and a blank of detecting the melamine content in multiple samples by the ion chromatography is filled up.

The invention discloses a method for preparing a cadmium ion adsorbent in water through wheat straws subjected to combined pretreatment based on dilute sulfuric acid and DDBAC (Dodecyldimethyl Ammonium Chloride) and belongs to the technical field of waste recycling and wastewater treatment. The method disclosed by the invention comprises the following steps: (1) physically treating wheat straws; (2) chemically treating the wheat straws; (3) cleaning; and (4) performing an adsorption experiment. The method is simple and readily available in raw materials, economical and high in efficiency, hashigh efficiency of adsorbing and removing cadmium ions in the water, does not cause secondary pollution, has wide prospects in the field of treatment of heavy metal polluted wastewater, and can achieve an aim of recycling the wastes.

The invention discloses a graphite loaded tin dioxide electrode and a preparation method. The preparation method comprises the following steps of (1) grinding a graphite sheet with abrasive paper so as to remove a surface inert layer, and then performing oxygen terminal treatment; putting a graphite electrode obtained after treatment in a muffle furnace, and performing heat treatment by adopting temperature programming in carbon dioxide atmosphere, so that a standby graphite sheet is obtained; (2) preparing sol-gel deposition liquid; and (3) repeating impregnation-deposition, drying and calcining processes for many times, so that an SnO2-Mn / Graphite electrode is prepared. According to the preparation method, the surface structure of an SnO2 coating is reformed by utilizing manganese as a metal element, so that an Mn doped SnO2 modified layer with small particle size and compact arrangement is obtained, and the electrode performance is improved; compared with the graphite sheet which isnot modified, the obtained electrode has high oxygen evolution potential and electrocatalytic activity, and the stability of the graphite electrode can be effectively kept.

The invention provides a analysis and detection method of gas free radical in the mainstream smoke of cigarette, characterized by: using MALDI-FT-ICR-MS to detect the gas radical in mainstream smoke of cigarettes, concrete steps include: 1) choosing radical trap agent; 2) trapping gas radical in the gas; 3) choosing radical character; 4) Pointing and entering MALDI-FT-ICR-MS analysis; 5) analysis of spectrum analytical data; 6) further checking out the cigarettes free radical and its adducts in mainstream smoke of cigarettes. Advantages ars: MALDI-MS FT-ICR-soft ionization technology, high-resolution and high sensitivity can provide accurate analysis of the molecular mass, elemental composition, molecular structure and experience of information, to distinguish between two compounds in the mixture of very molecular weight nearly, is qualitative specific, sensitive, rapid and convenient detection advantage, but also suitable for high-throughput experiments. It provides a very favorable analytical tool for radical research and development.

The invention discloses a fast detecting method for sulfonamide residues in shrimps. Methyl alcohol is used for extracting the sulfonamide residues in shrimp mince, stable fuchsia derivatives are formed through a fast derivation reaction of the sulfonamide residues and a specific derivatization reagent, a color development result is observed through the naked eyes so that fast detection can be achieved, and the detection sensitivity can reach 50 microgram per kilogram at least. The fast detection method is simple in pretreatment, short in detection time and low in detection cost, a large instrument is not needed, field detection can be achieved, color changes are observed through the naked eyes so that the detection result can be rapidly obtained, and the sulfonamide residues in the shrimps can be rapidly and efficiently detected.

The invention belongs to the field of oil and gas exploration and research, and particularly provides an ancient fluid comprehensive analysis method related to oil and gas accumulation. The method comprises the main steps of calcite sample collection and screening, cathodoluminescence analysis, hydrocarbon-containing fluid inclusion identification, fluid inclusion uniform temperature measurement,fluid inclusion laser Raman analysis, laser in-situ calcite vein U-Pb dating, calcite and surrounding rock C-O isotope analysis, calcite and surrounding rock Sr isotope analysis and the like. According to the method, the hydrocarbon-containing calcite related to oil and gas accumulation serves as a research object, the activity age and hydrocarbon-containing components of the hydrocarbon-containing fluid can be determined, the temperature and source of the hydrocarbon-containing fluid can be found out, and the problems that in the prior art, age information is lost, a tracing method is single,and interpretation subjectivity is high can be effectively solved.

The invention discloses a method for measuring the content of lactoferrin in infant milk powder, which comprises the following steps: adding to-be-measured infant milk powder into a phosphate buffer solution A to completely dissolve the infant milk powder, and adjusting the pH value to be acidic to form casein precipitate to obtain a mixed solution; centrifugally separating the mixed solution, taking supernate, and adding the phosphate buffer solution A to obtain a sample injection solution; and taking the sample injection solution, and detecting the sample injection solution in high performance liquid chromatography, wherein a chromatographic column of the high performance liquid chromatography is a heparin affinity column. According to the method, impurity proteins in the infant milk powder are precipitated by adjusting the pH value, then a high performance liquid chromatograph (the chromatographic column is a HiTrapTMHeparin HP (1mL) heparin affinity column) is directly used for determination, and a target object is extracted through buffer salt. According to the method, the pretreatment steps are optimized, and the heparin affinity column is used for determination, so that the method is simple, and the detection efficiency is high.

The invention relates to a simplified incremental iteration method suitable for calculating ultimate strength of a luxurious cruise ship. The method comprises: establishing luxury cruise ship cross section calculation model; calculating the shearing rigidity, the ultimate shearing displacement and the total shearing rigidity of each supporting component of the conversion layer, and obtaining the ultimate shearing displacement of the whole conversion layer through comparison; respectively calculating initial neutralization elastic neutralization axis positions of the main hull and the superstructure; adjusting the position of a neutralizing shaft, and calculating longitudinal tension and pressure of the superstructure and the main hull until tension and pressure balance of the superstructure and the main hull is realized; obtaining the total bending moment on the cross section of the whole hull beam and the average shear displacement of the conversion layer; increasing curvatures of themain hull and the superstructure, and calculating corresponding strain and corresponding stress of each unit; and stopping increasing the curvature until the average shear displacement of the conversion layer reaches the limit shear displacement, and outputting the total bending moment. The method has high precision and efficiency.

The invention discloses a method for analyzing protein adulteration in dairy products. The method comprises the following steps of: dividing a sample into two parts, performing alkaline hydrolysis on one part of the sample, and performing acidolysis on the other part of the sample; neutralizing by using acid after alkaline hydrolysis, drying by distillation after acidolysis, redissolving by using dilute acid, derivatizing the redissolved liquid by using derivating agents, and filtering by using an organic filter membrane so as to obtain sample liquor; respectively preparing a tryptophan standard solution and a mixed standard solution of threonine, valine and lysine; and respectively injecting the standard solutions and the sample liquor into a high performance liquid chromatograph, then measuring the peak area of the standard solutions and the peak area of the sample liquor, and calculating the content of the tryptophan, the threonine, the valine and the lysine in the sample liquor. The method is simple in operation, low in analysis cost and easy to popularize and apply, and an analysis result can be obtained quickly.

The invention discloses a method for determining the content of azodicarbonamide in the leather by HPLC (high performance liquid chromatography). The method comprises the following steps: step 1, preparing three samples; step 2, performing HPLC determination on the three solutions prepared in step 1 under the condition of HPLC. With adoption of the method, detection of the content of azodicarbonamide in leather can be well controlled, health and safety of consumers are guaranteed, pretreatment is simple, and the method can be used for accurately detecting the content of azodicarbonamide in theleather.

The invention provides a method and a detection kit for identifying a biomarker of cerebral hemorrhage. The biomarker is free mannose and glucose obtained by high performance liquid chromatography based on pre-column 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization in serum. The detection method is the high performance liquid chromatography method based on the pre-column PMP derivatization. Thetechnical scheme has the advantages that the pretreatment is simple, the analysis time is short, the instrument price is reasonable, the requirements of conventional use are met, the operation stepsare simple and easy to learn, and the accuracy of a detection result is high, a normal person and a cerebral hemorrhage patient can be distinguished only by blood collection, the amount of the neededserum is extremely small, the blood collection amount is smaller than 1 mL, and the like. The obtained result shows that the analysis method can be used for rapidly determining the content of the freemannose and glucose in the serum of the cerebral hemorrhage patient, so that the method has very important significance for researching a relation between the free mannose and glucose in the serum and the cerebral hemorrhage, and looking for a novel cerebral hemorrhage clinical detection marker.

The invention discloses a crop straw degradation pretreatment method which comprises the following steps: in an ionic membrane electrolytic cell, dividing the ionic membrane electrolytic cell into a salt adding area, an anode area and a cathode area by adopting homogeneous anion and cation exchange membranes; adding a sodium chloride aqueous solution as an electrolyte into the salting area, and carrying out constant-current electrolysis to obtain acidic oxidized electrolyzed water in the anode area and alkaline reduced electrolyzed water in the cathode area; the method comprises the followingsteps: putting crop straws into alkaline reduction electrolytic water, heating and stirring for pretreatment; then putting into acidic oxidized electrolyzed water, heating, stirring and pre-treating;putting the pretreated crop straws into a buffer solution, and then adding an enzyme solution for enzymolysis; the acidic oxidized electrolyzed water is combined with the alkaline reduced electrolyzedwater to pretreat the straws, so that the removal effect of hemicellulose and lignin in the straws is effectively improved, the enzymolysis efficiency of subsequent steps is improved, and the methodis safe and environment-friendly.