CN104697983A - Method of detecting heavy metal lead, cadmium, arsenic and copper in TCM (Traditional Chinese Medicine) tablet - Google Patents

Abstract

The invention discloses a method of detecting heavy metal lead, cadmium, arsenic and copper in a TCM (Traditional Chinese Medicine) tablet. The method comprises the following steps: after carrying out microwave alkaline hydrolysis on tablet powder with an ammonia chloride containing diluted alkali solution, quickly adding hydrogen peroxide containing dilute acid solution, and ultrasonically extracting after the pH value is adjusted to be not more than 2; carrying out constant volume on an extract after the centrifugation, condensation and microfiltration; and finally, determining by adopting an atomic absorbency method. According to the method, a sample is preprocessed by an alkaline-hydrolysis acid-extracting method, therefore, the loss of heavy metal element caused by high temperature of a dry ashing method and air pollution and potential danger caused by a resolution method can be prevented; meanwhile, the method has the advantages of being good in recovery rate, high in precision, fast in processing speed, convenient to operate, wide in range of application and the like, and is more suitable for the quantitative determination of trace metal elements.

Description

The detection method of heavy metal lead, cadmium, arsenic, copper in a kind of prepared slices of Chinese crude drugs

Technical field

The invention belongs to technical field of analysis and detection, be specifically related to the detection method of heavy metal lead, cadmium, arsenic, copper in a kind of prepared slices of Chinese crude drugs.

Background technology

Chinese medicine is the rarity of the traditional medicine of China, the Chinese nation.The quality of its medicine materical crude slice directly affects the effect that the traditional Chinese medical science is cured the disease.Chinese medicine is produced through gathering, transporting, store in a warehouse from field, again to processing, concoct until finally become pharmacy and buy for people, in the complex process of finished product medicine materical crude slice taken, there is several factors can affect content of beary metal wherein, such as, planting soil, the agriculture chemical used, process of preparing Chinese medicine vessel etc.For ensureing drug safety, China's " green industry standard imported and exported by medicinal plant and preparation " makes limitation to medicinal plant and preparation: total metals answers≤20.0mg/kg, plumbous (Pb)≤5.0mg/kg, cadmium (Cd)≤0.3mg/kg, mercury (Hg)≤0.2mg/kg, copper (Cu)≤20.0mg/kg, arsenic (As)≤2.0mg/kg.Meanwhile, the detection of heavy metal in medicine materical crude slice is also listed in quality standard by Chinese Pharmacopoeia.And if Chinese medicine is gone abroad, participating in the competition of world pharmaceutical market, is also imperative to the control of heavy metal element in its medicine materical crude slice.Therefore, the detection method studying content of beary metal in a kind of effective mensuration prepared slices of Chinese crude drugs is significant.

At present, its detection method of recommending of China's " green industry standard imported and exported by medicinal plant and preparation " mainly contains colourimetry and ultraviolet spectrophotometry.The quantivative approach that Chinese Pharmacopoeia specifies is atomic absorption spectrophotometry, Limit Test method is colourimetry, and the method for inspection of heavy metal mostly is the modern equipment analytical approachs such as atomic fluorescence spectrometry, inductively coupled plasma emission spectrography and atomic absorption spectrophotometry in a lot of developed country's pharmacopeia and commercial quality test stone, therefore, adopt the modern equipment analytical approach of the high precision such as atomic absorption spectrophotometry and sensitivity be heavy metal quantitatively in a trend, and replace conventional chemical method gradually.

But adopt the content of atomic absorption spectroscopy determination heavy metal to need to carry out pre-service to testing sample, preprocess method conventional at present has dry ashing method, wet digestion method, Microwave Digestion, acid extraction method.Dry ashing method refers to and by high temperature (about 500 DEG C), organic substance in sample is all vapored away, and reaches the object of removing organic substance.This method Partial Elements loses by high temperature evaporation, and (part is due to the absorption of crucible or vessel, also some sample can react to generate with crucible and vessel and be difficult to use the material of acid dissolve as glass or refractory etc.), thus reducing accuracy and the precision of detection, the recovery only can reach about 40%.Wet digestion method is in appropriate sample, adds oxidisability strong acid, adds heat damage organism, inorganic constituents to be measured is discharged, forms nonvolatile mineral compound, measures to carry out analysis.This method sample processing time is longer, and at least need the time of a hours sometimes even to need to spend the night, and once can not digest more than 10 samples in experimentation, the labour intensity of method is larger.Reagent nitric acid, perchloric acid, sulfuric acid etc. that treatments of the sample uses often have corrosivity and more dangerous reagent.Operating process also can produce a large amount of acid mists and cigarette, and also very large to the corrosivity of fuming cupboard, misoperation even can be blasted, and danger is higher.Although the recovery of this method and precision are better than dry ashing method, but still desirable not to the utmost.Microwave Digestion refers to the penetrability and activating reaction ability that utilize microwave, sample temperature is raised, adopts packoff simultaneously, add a certain amount of acid solution, reach the object making organic material decomposition in sample.This method sample volume is very little, general solid sample is less than 1g, fluid sample is less than 2mL, pre-service (placement spend the night or sub zero treatment etc.) must be carried out before Specimen eliminating simultaneously, the digestion solution processed also must be caught up with except the residual acid in liquid and oxides of nitrogen (wet digesting also need) etc., produce a large amount of acid mists and cigarette, cause air pollution.It should be noted that most owing to using microwave heating, the leakage of microwave to be prevented in experimentation, but also need pay special attention to grasp the relation cleared up between the kind of sample and sample weighting amount, strict control reflection condition, prevent counteracting tank to be out of shape because pressure is excessive, cause potential safety hazard.The equal time and effort consuming of these methods is dangerous high.Acid extractants refers to selects certain acid the element extraction to be measured in sample out to be measured.This method has the advantage that the recovery is good, precision is high, speed is fast, easy and simple to handle, safe and free from environmental pollution, but this method is only applicable to, and composition is single does not contain organic sample, and for the plant sample of complicated component, only the heavy metal element existed in a variety of forms in plant cannot extract completely by acid extractants, cause the on the low side of result, and be difficult to remove totally containing small organic matter particle in extract, be not suitable for the mensuration of atomic absorption spectrophotometry.

Summary of the invention

The technical issues that need to address of the present invention are to provide the detection method of heavy metal lead, cadmium, arsenic, copper in a kind of prepared slices of Chinese crude drugs, and the method sensitivity is good, and preci-sion and accuracy is high, and simple, safe, free from environmental pollution, the applied widely model of pre-service.

For solving the problem, the technical solution that the present invention takes is:

A detection method for heavy metal lead, cadmium, arsenic, copper in the prepared slices of Chinese crude drugs, comprises sample pretreatment and the large step of quantitative measurement two;

Described sample pretreating method is as follows:

Step one, alkaline hydrolysis: precision takes prepared slices of Chinese crude drugs powder 5g, adds the dilute alkaline soln that 10mL contains ammonium chloride, through microwave treatment after jolting, obtain alkaline hydrolysis sample solution;

Step 2, acid are carried: dilute acid soln 20mL being contained hydrogen peroxide, join rapidly under agitation in the alkaline hydrolysis sample solution of step one gained, detect pH value of solution, if pH value is greater than 2, adjust pH is to after being less than or equal to 2, carry out ultrasonic extraction, centrifugal, the described dilute acid soln containing hydrogen peroxide of residue washs, centrifugal, merge supernatant, obtain crude extract; The described dilute acid soln containing hydrogen peroxide is prepared before use;

Step 3, concentrated: crude extract step 2 obtained adopts rotary evaporating device to concentrate, and obtains concentrate;

Step 4, micro-filtration: concentrate step 3 the obtained filtering with microporous membrane of 0.2 μm, obtains smart filtrate;

Step 5, constant volume: the dilution of dilute acid soln described in smart filtrate step 2 step 4 obtained also constant volume, obtains prepared slices of Chinese crude drugs sample solution, i.e. need testing solution;

Described method for quantitatively determining is as follows:

Steps A, prepare blank solution: measure the dilute alkaline soln containing ammonium chloride described in 10mL step one, after microwave treatment, add rapidly the dilute acid soln containing hydrogen peroxide described in 20mL step 2 under agitation, detect pH value of solution, if pH value is greater than 2, adjust pH is to after being less than or equal to 2, carry out ultrasonic process, centrifugal, the described dilute acid soln containing hydrogen peroxide of residue washs, centrifugal, after merging supernatant, through rotary evaporating device concentration, then the filtering with microporous membrane of described in step 4 0.2 μm is used, last constant volume, obtain blank solution,

Step B, quantitative measurement: adopt atomic absorption spectrophotometry to carry out quantitative measurement to step 5 gained need testing solution.

Further, dilute alkaline soln described in step one is one or both in NaOH, potassium hydroxide, and concentration is 0.2 ~ 1.0mol/L, and the concentration of described ammonium chloride is massfraction 10%.

Further, dilute acid soln described in step 2 is one or more in salpeter solution, sulfuric acid solution, hydrochloric acid solution, citric acid solution, and concentration is more than or equal to 0.2mol/L; The concentration of described hydrogen peroxide is massfraction 5%.

Further, the miillpore filter described in step 3 is PEFT material.

Further, the power of microwave treatment described in step one is 800 ~ 1500W, time 30 ~ 90s, and the time of ultrasonic extraction described in described step 2 is for being more than or equal to 20min.

Further, in step one, dilute alkaline soln used is sodium hydroxide solution, the concentration of sodium hydroxide solution is 0.5mol/L, microwave power is 800W, the microwave time is 30s, dilute acid soln described in step 2 is hydrochloric acid solution, and the concentration of hydrochloric acid solution is 0.5mol/L, and described ultrasonic extraction time is 20min.

Further, employing atomic absorption spectrophotometry described in described step B is respectively: plumbous mensuration adopts graphite furnace-atomic absorption, Cadmium detrmination adopts graphite furnace-atomic absorption, the mensuration of arsenic adopts hydride generation-atomic absorption photometry, Cupper determination adopts NITRATE BY FLAME ATOMIC absorption photometry

The concrete steps of atomic absorption spectrophotometry comprise following three parts:

The setting of Part I, Instrument measuring parameter:

Plumbous condition determination: wavelength 283.3nm, baking temperature 100 ~ 120 DEG C, continues 20 seconds, ashing temperature 400 ~ 750 DEG C, continues 20 ~ 25 seconds; Atomization temperature 1700 ~ 2100 DEG C, continues 4 ~ 5 seconds;

Cadmium detrmination condition: wavelength 228.8nm, baking temperature 100 ~ 120 DEG C, continues 20 seconds, ashing temperature 300 ~ 500 DEG C, continues 20 ~ 25 seconds; Atomization temperature 1500 ~ 1900 DEG C, continues 4 ~ 5 seconds;

The condition determination of arsenic: adopt hydride generation system, using the sodium hydroxide solution of the massfraction 0.3% containing massfraction 1% sodium borohydride as reductive agent, hydrochloric acid solution is carrier fluid, and nitrogen is carrier gas, and determined wavelength is 193.7nm; The sodium hydroxide solution of the described massfraction 0.3% containing massfraction 1% sodium borohydride configures before use, this hydrochloric acid solution to be commercial available quality mark be 36% hydrochloric acid carry out 100 times of dilution gained;

Cupper determination condition: determined wavelength is 327nm, adopts Air-acetylene Flame, carries out background correction if desired;

The preparation of Part II, typical curve:

The compound method of dilution is: the dilute alkaline soln containing ammonium chloride described in the step one measuring 10mL, adds the dilute acid soln containing hydrogen peroxide described in 20mL step 2, then with described dilute acid soln constant volume, obtains dilution;

The preparation of plumbous typical curve: precision measures plumbous single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the plumbous single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate plumbous single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes the solution of every 1mL leaded 0ng, 5ng, 20ng, 40ng, 60ng, 80ng respectively; Then precision measures each concentration containing lead solution 1mL respectively, the accurate solution 0.5mL added containing massfraction 1% ammonium dihydrogen phosphate (ADP) and massfraction 0.2% magnesium nitrate respectively, after mixing, the accurate 20 μ L that draw inject graphite furnace atomizer respectively, measure absorbance, with absorbance for vertical cursor, concentration is horizontal ordinate, drawing standard curve;

The preparation of cadmium typical curve: precision measures cadmium single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the cadmium single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate cadmium single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes every 1mL respectively containing the solution of cadmium 0ng, 0.8ng, 2.0ng, 4.0ng, 6.0ng, 8.0ng; Then precision draws each concentration cadmium-containing solution 10 μ L respectively, injects graphite furnace atomizer, and measure absorbance, take absorbance as ordinate, concentration is horizontal ordinate, drawing standard curve;

The preparation of arsenic typical curve: precision measures arsenic single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the arsenic single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate arsenic single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes every 1mL respectively containing the solution of arsenic 0ng, 5ng, 10ng, 20ng, 30ng, 40ng; Then precision measures each concentration arsenic containing solution 10mL respectively, put in 25mL measuring bottle, add the liquor kalii iodide 1mL that massfraction is 25%, shake up, add the ascorbic acid solution 1mL that massfraction is 10%, shake up, be diluted to scale with hydrochloric acid solution, this hydrochloric acid solution to be commercial available quality mark be 36% hydrochloric acid 5 times dilution gained, shake up, close plug, put in 80 DEG C of water-baths and heat 3 minutes, take out, let cool rear suction hydride generation system, measure absorption value, with peak area or absorbance for ordinate, concentration is horizontal ordinate, drawing standard curve; Described massfraction be 25% liquor kalii iodide and massfraction be 10% ascorbic acid solution be and configure before use;

The preparation of copper typical curve: precision measures copper single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the copper single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate copper single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes the solution of every 1mL leaded 0 μ g, 0.05 μ g, 0.2g, 0.4 μ g, 0.6 μ g, 0.8 μ g respectively; Then get the copper-containing solution of each concentration gradient respectively, spray into flame successively, measure absorbance, take absorbance as ordinate, concentration is horizontal ordinate, drawing standard curve;

The mensuration of content of beary metal in Part III, need testing solution:

Plumbous mensuration: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, after record extension rate, each precision measures 1mL, the accurate solution 0.5mL added containing massfraction 1% ammonium dihydrogen phosphate (ADP) and massfraction 0.2% magnesium nitrate respectively, mixing, accurate absorption 20 μ L, absorbance is measured with condition described in Part I, read content plumbous in need testing solution from typical curve, calculate, to obtain final product;

Cadmium detrmination: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, after record extension rate, each precision draws 10 μ L, absorbance is measured with condition described in Part I, read the content of cadmium in need testing solution from typical curve, calculate, to obtain final product;

Arsenic determination method: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, after record extension rate, each precision measures 10mL, put in 25mL measuring bottle, add the liquor kalii iodide 1mL that massfraction is 25%, shake up, add the ascorbic acid solution 1mL that massfraction is 10%, shake up, scale is diluted to hydrochloric acid solution, this hydrochloric acid solution to be commercial available quality mark be 36% hydrochloric acid 5 times dilution gained, shake up, close plug, put in 80 DEG C of water-baths and heat 3 minutes, take out, let cool rear suction hydride generation system, absorption value is measured with condition described in Part I, the content of arsenic in need testing solution is read from typical curve, calculate, obtain, described massfraction be 25% liquor kalii iodide and massfraction be 10% ascorbic acid solution be and configure before use,

Copper determination method: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, after record extension rate, sprays into flame successively, absorbance is measured with condition described in Part I, read the content of copper in need testing solution from typical curve, calculate, to obtain final product.

The present invention has the following advantages:

1, the present invention breaks through traditional dry ashing and digestion procedure, alkaline hydrolysis acid formulation is adopted to carry out pre-service to sample, the air pollution that the loss of the heavy metal element that the high temperature avoiding dry ashing method causes and resolution method cause and potentially danger, have the advantages such as the recovery is good, precision is high, processing speed is fast, easy and simple to handle, applicable wide model simultaneously.

2, the present invention adds alkaline hydrolysis step on the basis of acid extractants, the heavy metal of multiple existing forms in the prepared slices of Chinese crude drugs can be discharged, add the accuracy of sample determination, and alkaline hydrolysis step makes the filtercondition of extract be relaxed, only adopt the method for micro-filtration just can reach the requirement of atomic absorption to sample determination, and lacking this step, extract is even difficult to through ultrafiltration or nanofiltration the mensuration requirement reaching atom spectrophotometric method.

3, the present invention adds ammonium chloride in alkaline hydrolysis process, reduces the settling rate of heavy metal ion, make the extraction of heavy metal ion more abundant, and alkaline hydrolysis process adopts microwave heating, makes alkaline hydrolysis more thorough more rapidly.

4, the present invention carries in process in acid and adds hydrogen peroxide, accelerates the release of complexation of metal ions, makes extraction more abundant.

5, invention increases concentration step, the low-down sample of heavy metal element, after can increasing sample weighting amount, concentration is carried out to crude extract, to improve the concentration of heavy metal in need testing solution, thus add the sensitivity of sample determination, be more suitable for the quantitative of trace metal element.

6, inventive samples after pretreatment, can be used for the mensuration of detection device for multi metallic elements, do not need every Heavy Metallic Elements to carry out separately the pre-service of sample, decrease workload.

Accompanying drawing explanation

Fig. 1 is the canonical plotting of heavy metal lead;

Fig. 2 is the canonical plotting of heavy metal cadmium;

Fig. 3 is the canonical plotting of heavy metal arsenic;

Fig. 4 is the canonical plotting of heavy metal copper.

Embodiment

Below in conjunction with specific embodiment, the present invention will be further described.

In the present invention, the single element solution reference material of lead used, cadmium, arsenic and copper is all purchased from national standard material development center, and concentration is 100mg/L.

The present invention all picks up from Hebei gold wooden medicine company test garden for method research institute baikal skullcap root, the capsule of weeping forsythia, honeysuckle, Radix Glycyrrhizae, in the growth course of medicinal material, heavy metal element lead, cadmium, arsenic, copper are regularly sprayed to it, the method specified by Chinese Pharmacopoeia after gathering is concocted, obtained medicine materical crude slice, to guarantee in test material therefor containing heavy metal lead, cadmium, arsenic, copper.In the present invention, other prepared slices of Chinese crude drugs used are commercially available.In the present invention, pre-service and the testing conditions research institute prepared slices of Chinese crude drugs are the root of large-flowered skullcap, the evaluation of methodology prepared slices of Chinese crude drugs used are the root of large-flowered skullcap, the capsule of weeping forsythia, honeysuckle, Radix Glycyrrhizae, and it is the root of large-flowered skullcap, the capsule of weeping forsythia, honeysuckle, Radix Glycyrrhizae, notopterygium root, sealwort, dried orange peel, windproof, Radix Angelicae Sinensis, the rhizome of Chinese monkshood, the wind-weed, the Radix Astragali, safflower that method contrasts the prepared slices of Chinese crude drugs used.The present invention's prepared slices of Chinese crude drugs used are powder, are gained after medicine materical crude slice pulverization process.

TAS-990 type atomic absorption spectrophotometer (AAS) is purchased from Beijing Puxi General Instrument Co., Ltd.

The type of alkali used and the impact of concentration heavy metal assay thereof in embodiment 1 step one

The present embodiment prepared slices of Chinese crude drugs used are the root of large-flowered skullcap.

Sample pretreating method is as follows:

Step one, alkaline hydrolysis: get prepared slices of Chinese crude drugs powder 5g, add the dilute alkaline soln that 10mL contains massfraction 10% ammonium chloride, through 800W microwave treatment 30s after jolting, obtain alkaline hydrolysis sample solution;

Step 2, acid are carried: (this dilute acid soln is the hydrochloric acid solution of 0.5mol/L 20mL to be contained the dilute acid soln of massfraction 5% hydrogen peroxide, prepared before use), join rapidly under agitation in the alkaline hydrolysis sample solution of step one gained, detect pH value of solution, if pH value is greater than 2, with described dilute acid soln (not containing hydrogen peroxide) adjust pH to after being less than or equal to 2, ultrasonic extraction 20min, centrifugal, residue is with after the described dilute acid soln washing containing massfraction 5% hydrogen peroxide, centrifugal, merge supernatant, obtain crude extract;

Step 3, concentrated: crude extract step 2 obtained adopts rotary evaporating device to concentrate, and obtains concentrate;

Step 4, micro-filtration: concentrate step 3 the obtained PEFT filtering with microporous membrane of 0.2 μm, obtains smart filtrate;

Step 5, constant volume: by dilute acid soln (not containing hydrogen peroxide) the dilution also constant volume (this root of large-flowered skullcap sample is settled to 100mL) described in the smart filtrate step 2 of step 4 gained, obtain prepared slices of Chinese crude drugs sample solution, i.e. need testing solution;

Method for quantitatively determining is as follows:

Steps A, prepare blank solution: measure the dilute alkaline soln containing massfraction 10% ammonium chloride described in 10mL step one, after microwave treatment, add rapidly the dilute acid soln containing massfraction 5% hydrogen peroxide described in 20mL step 2 under agitation, detect pH value of solution, if pH value is greater than 2, adjust pH is to after being less than or equal to 2, carry out ultrasonic process, centrifugal, the described dilute acid soln containing hydrogen peroxide of residue washs, centrifugal, after merging supernatant, through rotary evaporating device concentration, then the PEFT filtering with microporous membrane of described in step 4 0.2 μm is used, last constant volume, obtain blank solution,

Step B, quantitative measurement: adopt atomic absorption spectrophotometry to carry out quantitative measurement to step 5 gained need testing solution; Be specially plumbous mensuration and adopt graphite furnace-atomic absorption, Cadmium detrmination adopts graphite furnace-atomic absorption, the mensuration of arsenic adopts hydride generation-atomic absorption photometry, Cupper determination adopts NITRATE BY FLAME ATOMIC absorption photometry, and the step of atomic absorption spectrophotometry specifically comprises following three parts:

The setting of Part I, Instrument measuring parameter:

Plumbous mensuration adopts graphite furnace-atomic absorption, and impose a condition as wavelength 283.3nm, baking temperature 110 DEG C, continues 20 seconds, ashing temperature 600 DEG C, continue 25 seconds; Atomization temperature 1800 DEG C, continues 5 seconds;

Cadmium detrmination adopts graphite furnace-atomic absorption, imposes a condition as wavelength 228.8nm, baking temperature 110 DEG C, continues 20 seconds, ashing temperature 500 DEG C, continue 25 seconds; Atomization temperature 1800 DEG C, continues 5 seconds;

The mensuration of arsenic adopts hydride generation-atomic absorption photometry, impose a condition for: adopt hydride generation system, using the sodium hydroxide solution (prepared before use) of the massfraction 0.3% containing massfraction 1% sodium borohydride as reductive agent, hydrochloric acid solution (1 → 100) is carrier fluid, nitrogen is carrier gas, and determined wavelength is 193.7nm; The sodium hydroxide solution of the described massfraction 0.3% containing massfraction 1% sodium borohydride configures before use, this hydrochloric acid solution to be commercial available quality mark be 36% hydrochloric acid carry out 100 times of dilution gained;

Cupper determination adopts NITRATE BY FLAME ATOMIC absorption photometry, impose a condition for: determined wavelength is 327nm, adopts Air-acetylene Flame, carries out background correction if desired;

The preparation of Part II, typical curve:

The compound method of dilution is: the dilute alkaline soln containing massfraction 10% ammonium chloride described in the step one measuring 10mL, add the dilute acid soln containing massfraction 5% hydrogen peroxide described in 20mL step 2, then with described dilute acid soln (not containing hydrogen peroxide) constant volume, dilution is obtained;

The preparation of plumbous typical curve: precision measures plumbous single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the plumbous single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate plumbous single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes the solution of every 1mL leaded 0ng, 5ng, 20ng, 40ng, 60ng, 80ng respectively; Then precision measures each concentration containing lead solution 1mL respectively, the accurate solution 0.5mL added containing massfraction 1% ammonium dihydrogen phosphate (ADP) and massfraction 0.2% magnesium nitrate respectively, after mixing, the accurate 20 μ L that draw inject graphite furnace atomizer respectively, measure absorbance, with absorbance for vertical cursor, concentration is horizontal ordinate, drawing standard curve;

The preparation of cadmium typical curve: precision measures cadmium single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the cadmium single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate cadmium single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes every 1mL respectively containing the solution of cadmium 0ng, 0.8ng, 2.0ng, 4.0ng, 6.0ng, 8.0ng; Then precision draws each concentration cadmium-containing solution 10 μ L respectively, injects graphite furnace atomizer, and measure absorbance, take absorbance as ordinate, concentration is horizontal ordinate, drawing standard curve;

The preparation of arsenic typical curve: precision measures arsenic single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the arsenic single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage, the accurate arsenic single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes every 1mL respectively containing the solution of arsenic 0ng, 5ng, 10ng, 20ng, 30ng, 40ng, then precision measures each concentration arsenic containing solution 10mL respectively, put in 25mL measuring bottle, add liquor kalii iodide (prepared before use) 1mL that massfraction is 25%, shake up, add ascorbic acid solution (prepared before use) 1mL that massfraction is 10%, shake up, scale is diluted to hydrochloric acid solution (20 → 100), this hydrochloric acid solution to be commercial available quality mark be 36% hydrochloric acid 5 times dilution gained, shake up, close plug, put in 80 DEG C of water-baths and heat 3 minutes, take out, let cool rear suction hydride generation system, measure absorption value, with peak area or absorbance for ordinate, concentration is horizontal ordinate, drawing standard curve, described massfraction be 25% liquor kalii iodide and massfraction be 10% ascorbic acid solution be and configure before use,

The preparation of copper typical curve: precision measures copper single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the copper single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate copper single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes the solution of every 1mL leaded 0 μ g, 0.05 μ g, 0.2g, 0.4 μ g, 0.6 μ g, 0.8 μ g respectively; Then get the copper-containing solution of each concentration gradient respectively, spray into flame successively, measure absorbance, take absorbance as ordinate, concentration is horizontal ordinate, drawing standard curve;

The mensuration of content of beary metal in Part III, need testing solution

Plumbous mensuration: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, record extension rate after (final concentration after dilution with survey absorbance be advisable between 0 ~ 1, this root of large-flowered skullcap sample is 2.5 times of dilutions), each precision measures 1mL, the accurate solution 0.5mL added containing massfraction 1% ammonium dihydrogen phosphate (ADP) and massfraction 0.2% magnesium nitrate respectively, mixing, accurate absorption 20 μ L, absorbance is measured with condition described in Part I, content plumbous in need testing solution is read from typical curve, calculate, to obtain final product;

Cadmium detrmination: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, record extension rate after (final concentration after dilution with survey absorbance be advisable between 0 ~ 1, this root of large-flowered skullcap sample is 2.5 times of dilutions), each precision draws 10 μ L, absorbance is measured (if test sample has interference with condition described in Part I, precision can measure standard solution respectively, blank solution and each 1mL of need testing solution, precision adds the solution 0.5mL containing massfraction 1% ammonium dihydrogen phosphate (ADP) and massfraction 0.2% magnesium nitrate, mixing, measure) in accordance with the law, the content of cadmium in need testing solution is read from typical curve, calculate, obtain,

Arsenic determination method: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, record extension rate after (final concentration after dilution with survey absorbance be advisable between 0 ~ 1, this root of large-flowered skullcap sample is 2.5 times of dilutions), each precision measures 10mL, put in 25mL measuring bottle, add liquor kalii iodide (prepared before use) 1mL that massfraction is 25%, shake up, add ascorbic acid solution (prepared before use) 1mL that massfraction is 10%, shake up, scale is diluted to hydrochloric acid solution (20 → 100), this hydrochloric acid solution to be commercial available quality mark be 36% hydrochloric acid 5 times dilution gained, shake up, close plug, put in 80 DEG C of water-baths and heat 3 minutes, take out, let cool rear suction hydride generation system, absorption value is measured with condition described in Part I, the content of arsenic in need testing solution is read from typical curve, calculate, obtain,

Copper determination method: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, record extension rate after (final concentration after dilution with survey absorbance be advisable between 0 ~ 1, this root of large-flowered skullcap sample is 2.5 times of dilutions), spray into flame successively, absorbance is measured with condition described in Part I, read the content of copper in need testing solution from typical curve, calculate, to obtain final product.

Measurement result and analysis

(1) alkali used is sodium carbonate, NaOH and potassium hydroxide, when concentration is 0.5mol/L, the content of heavy metal lead, cadmium, arsenic, copper in the measured prepared slices of Chinese crude drugs, in table 1, all tests carry out 3 times parallel.

The type of table 1 alkali used is on the impact of heavy metal lead, cadmium, arsenic, copper mensuration in sample

The type of alkali	Plumbous μ g/g	Cadmium μ g/g	Arsenic μ g/g	Copper μ g/g
					Sodium carbonate	5.16±0.11	1.01±0.06	2.79±0.05	21.51±0.50
NaOH	10.51±0.25	2.07±0.05	6.05±0.06	50.93±0.94
					Potassium hydroxide	10.64±0.17	2.08±0.02	6.12±0.14	50.77±1.23

As can be seen from the table, alkaline hydrolysis need use highly basic, and weak base poor effect, NaOH and potassium hydroxide are preferably.

(2) adopt NaOH, concentration used be respectively 0,0.2,0.4,0.5,0.6,0.8,1.0,1.2,1.5mol/L time, the content of heavy metal lead, cadmium, arsenic, copper in the measured prepared slices of Chinese crude drugs, in table 2, all tests carry out 3 times parallel.

The concentration of table 2 aqueous slkali used is on the impact of heavy metal lead, cadmium, arsenic, copper mensuration in sample

Naoh concentration mol/L	Plumbous μ g/g	Cadmium μ g/g	Arsenic μ g/g	Copper μ g/g
					0	4.21±0.09	0.84±0.03	2.31±0.06	10.44±0.24
0.2	9.71±0.17	1.99±0.05	6.01±0.06	48.77±1.06
					0.4	10.29±0.16	2.02±0.06	6.05±0.11	49.31±0.61
0.5	10.39±0.21	2.09±0.06	6.08±0.06	50.72±0.78
					0.6	10.37±0.19	2.07±0.06	6.07±0.09	49.97±0.99
0.8	10.02±0.20	2.05±0.06	6.05±0.12	50.01±1.03
					1	9.93±0.18	1.97±0.05	6.02±0.11	48.61±1.01
1.2	9.17±0.16	1.69±0.05	5.94±0.10	47.22±0.76
					1.5	8.16±0.17	1.47±0.03	4.95±0.09	46.52±0.54
2	6.71±0.13	1.24±0.04	4.01±0.07	40.38±0.93

From table, data can draw, paper mill wastewater used is advisable with 0.2 ~ 1.0mol/L, and optimal concentration is 0.4 ~ 0.6mol/L.

The power of microwave treatment and the impact of processing time heavy metal assay in embodiment 2 step one

The present embodiment prepared slices of Chinese crude drugs used are the root of large-flowered skullcap.

Sample pretreating method is as follows:

Step one, alkaline hydrolysis: get prepared slices of Chinese crude drugs powder 5g, add the sodium hydroxide solution that 10mL contains the 0.5mol/L of massfraction 10% ammonium chloride, through microwave treatment after jolting, obtains alkaline hydrolysis sample solution;

Step 2 to step 5 with embodiment 1.

Method for quantitatively determining is with embodiment 1.

Measurement result and analysis

(1) microwave treatment power be 500,800,1000,1200,1500W, during processing time 30s, the content of heavy metal lead, cadmium, arsenic, copper in the measured prepared slices of Chinese crude drugs, in table 3, all tests carry out 3 times parallel.

The power of table 3 microwave treatment is on the impact of heavy metal lead, cadmium, arsenic, copper mensuration in sample

Microwave power W	Plumbous μ g/g	Cadmium μ g/g	Arsenic μ g/g	Copper μ g/g
					500	10.05±0.19	2.01±0.06	5.98±0.09	49.55±1.09
800	10.31±0.22	2.08±0.05	6.07±0.13	50.79±1.07
					1000	10.29±0.20	2.09±0.05	6.05±0.13	50.23±1.04
1200	10.35±0.18	2.08±0.05	6.08±0.11	50.81±0.89
					1500	10.3±0.21	2.07±0.06	6.06±0.12	50.94±0.77

As can be seen from the table, although microwave treatment power is not obvious on the impact of heavy metal lead, cadmium, arsenic, Cupper determination in sample, obtain power effect with 800W ~ 1500W optimum.

(2) microwave treatment power is 800W, and the processing time is respectively 0s, when 10s, 30s, 60s, 90s, 120s, 180s, the content of heavy metal lead, cadmium, arsenic, copper in the measured prepared slices of Chinese crude drugs, in table 4, all tests carry out 3 times parallel.

The impact that table 4 microwave treatment time measures heavy metal lead, cadmium, arsenic, copper in sample

Microwave time s	Plumbous μ g/g	Cadmium μ g/g	Arsenic μ g/g	Copper μ g/g
					0	7.01±0.11	1.54±0.04	3.21±0.05	40.43±0.86
10	9.25±0.19	1.94±0.05	5.31±0.08	48.16±0.93
					30	10.34±0.21	2.07±0.05	6.08±0.12	50.83±1.06
60	10.36±0.17	2.05±0.05	6.07±0.11	50.66±1.05
					90	10.29±0.21	2.06±0.06	6.07±0.12	50.71±1.07
120	10.01±0.20	2.00±0.05	5.85±0.13	49.15±1.02
					180	9.15±0.17	1.84±0.04	5.21±0.13	46.31±1.05

As can be seen from the table, microwave treatment time is advisable with 10s ~ 180s, and wherein 30s ~ 90s is optimum.

The type of acid used in embodiment 3 step 2 and the impact of concentration heavy metal assay

The present embodiment prepared slices of Chinese crude drugs used are the root of large-flowered skullcap.

Sample pretreating method is as follows:

Step one, alkaline hydrolysis: get prepared slices of Chinese crude drugs powder 5g, add the sodium hydroxide solution that 10mL contains the 0.5mol/L of massfraction 10% ammonium chloride, through 800W microwave treatment 30s after jolting, obtains alkaline hydrolysis sample solution;

Step 2, acid are carried: the dilute acid soln (prepared before use) 20mL being contained massfraction 5% hydrogen peroxide, join rapidly under agitation in the alkaline hydrolysis sample solution of step one gained, detect pH value of solution, if pH value is greater than 2, with described dilute acid soln (not containing hydrogen peroxide) adjust pH to being less than or equal to 2, then ultrasonic extraction 20min, centrifugal, residue is with after the described dilute acid soln washing containing massfraction 5% hydrogen peroxide, centrifugal, merge supernatant, obtain crude extract.

Step 3 to step 5 with embodiment 1.

Method for quantitatively determining is with embodiment 1.

Measurement result and analysis

(1) acid used is nitric acid, sulfuric acid, hydrochloric acid, citric acid, tartrate, when concentration is 0.5mol/L, the content of heavy metal lead, cadmium, arsenic, copper in the measured prepared slices of Chinese crude drugs, in table 5, all tests carry out 3 times parallel.

The type of table 5 acid used is on the impact of heavy metal lead, cadmium, arsenic, copper mensuration in sample

The type of acid	Plumbous μ g/g	Cadmium μ g/g	Arsenic μ g/g	Copper μ g/g
					Nitric acid	10.45±1.19	2.09±0.05	6.08±0.10	50.82±1.05
Sulfuric acid	10.41±1.17	2.07±0.05	6.09±0.11	50.76±1.05
					Hydrochloric acid	10.38±1.20	2.08±0.06	6.07±0.10	50.69±1.07
Citric acid	9.92±1.18	1.97±0.05	6.01±0.13	48.01±1.08
					Tartrate	9.85±1.21	1.02±0.04	5.44±0.12	46.53±1.09

As can be seen from the table, nitric acid, sulfuric acid, hydrochloric acid, citric acid and tartrate all may be used for landfill, wherein with nitric acid, sulfuric acid and hydrochloric acid extraction best results.

(2) acid used is hydrochloric acid, concentration is 0.1,0.3,0.5,0.7,1.0,1.5,2.0,2.5mol/L time, the content of heavy metal lead, cadmium, arsenic, copper in the measured prepared slices of Chinese crude drugs, in table 6, all tests carry out 3 times parallel.

The concentration of table 6 acid used is on the impact of heavy metal lead, cadmium, arsenic, copper mensuration in sample

The concentration mol/L of acid	Plumbous μ g/g	Cadmium μ g/g	Arsenic μ g/g	Copper μ g/g
					0.1	9.21±1.17	1.94±0.05	5.76±0.12	47.21±1.05
0.2	10.12±1.20	2.03±0.05	5.91±0.11	50.12±1.07
					0.5	10.36±1.21	2.09±0.06	6.06±0.13	50.58±1.06
0.8	10.38±1.21	2.08±0.04	6.05±0.12	50.66±1.06
					1	10.39±1.20	2.08±0.05	6.07±0.09	50.79±1.04
1.5	10.31±1.08	2.07±0.06	6.06±0.10	50.56±1.03
					2	10.35±1.19	2.05±0.06	6.04±0.12	50.43±0.95
2.5	10.32±1.17	2.06±0.05	6.06±0.13	50.42±1.02

As can be seen from the table, the concentration of acid used is advisable to be more than or equal to 0.2mol/L.

The impact of the time heavy metal assay of ultrasonic extraction in embodiment 4 step 2

The present embodiment prepared slices of Chinese crude drugs used are the root of large-flowered skullcap.

Sample pretreating method is as follows:

Step one, alkaline hydrolysis: get prepared slices of Chinese crude drugs powder 5g, add the sodium hydroxide solution that 10mL contains the 0.5mol/L of massfraction 10% ammonium chloride, through 800W microwave treatment 30s after jolting, obtains alkaline hydrolysis sample solution;

Step 2, acid is carried: (this dilute acid soln is hydrochloric acid solution 20mL to be contained the dilute acid soln of the 0.5mol/L of massfraction 5% hydrogen peroxide, the described dilute acid soln containing hydrogen peroxide is prepared before use), join rapidly under agitation in the alkaline hydrolysis sample solution of step one gained, detect pH value of solution, if pH value is greater than 2, with described dilute acid soln (not containing hydrogen peroxide) adjust pH to being less than or equal to 2, then after ultrasonic extraction, centrifugal, residue is with after the hydrochloric acid solution washing of the described 0.5mol/L containing massfraction 5% hydrogen peroxide, centrifugal, merge supernatant, obtain crude extract.

Step 3 to step 5 with embodiment 1.

Method for quantitatively determining is with embodiment 1.

Measurement result and analysis

(1) ultrasonic time be respectively 10,20,30,60min time, the content of heavy metal lead, cadmium, arsenic, copper in the measured prepared slices of Chinese crude drugs, in table 7, all tests carry out 3 times parallel.

The impact that table 7 ultrasonic extraction time measures heavy metal lead, cadmium, arsenic, copper in sample

Ultrasonic time min	Plumbous μ g/g	Cadmium μ g/g	Arsenic μ g/g	Copper μ g/g
					10	10.01±1.19	2.01±0.04	5.83±0.12	49.02±1.03
20	10.37±0.11	2.08±0.06	6.06±0.09	50.64±1.02
					30	10.33±0.16	2.09±0.03	6.06±0.11	50.84±1.05
60	10.39±0.18	2.09±0.06	6.05±0.11	50.77±1.07

As can be seen from the table, ultrasonic time is more than or equal to 20min extraction effect the best.

Embodiment 5

The present embodiment prepared slices of Chinese crude drugs used are the root of large-flowered skullcap.

Sample pretreating method is as follows:

Step one, alkaline hydrolysis: get prepared slices of Chinese crude drugs powder 5g, add the dilute alkaline soln (this dilute alkaline soln is sodium hydroxide solution) that 10mL contains massfraction 10% ammonium chloride, through 800W microwave treatment 30s after jolting, obtain alkaline hydrolysis sample solution;

Step 2, acid is carried: (this dilute acid soln is the hydrochloric acid solution of 0.5mol/L 20mL to be contained the dilute acid soln of massfraction 5% hydrogen peroxide, the described dilute acid soln containing hydrogen peroxide is prepared before use), join rapidly under agitation in the alkaline hydrolysis sample solution of step one gained, detect pH value of solution, if pH value is greater than 2, with described dilute acid soln (not containing hydrogen peroxide) adjust pH to after being less than or equal to 2, ultrasonic extraction 20min, centrifugal, residue is with after the described dilute acid soln washing containing massfraction 5% hydrogen peroxide, centrifugal, merge supernatant, obtain crude extract,

Step 3, concentrated: crude extract step 2 obtained adopts rotary evaporating device to concentrate, and obtains concentrate.

Step 4, micro-filtration: concentrate step 3 the obtained PEFT filtering with microporous membrane of 0.2 μm, obtains smart filtrate.

Step 5, constant volume: the dilute acid soln of 0.5mol/L described in the smart filtrate step 2 that step 4 is obtained (i.e. hydrochloric acid solution and not containing hydrogen peroxide) dilution constant volume (this root of large-flowered skullcap sample is settled to 100mL), obtain prepared slices of Chinese crude drugs sample solution, i.e. need testing solution;

Method for quantitatively determining is as follows:

Steps A, the preparation of blank solution: measure the dilute alkaline soln containing massfraction 10% ammonium chloride described in 10mL step one, after microwave treatment, add rapidly the dilute acid soln containing massfraction 5% hydrogen peroxide described in 20mL step 2 under agitation, detect pH value of solution, if pH value is greater than 2, adjust pH is to after being less than or equal to 2, carry out ultrasonic process, centrifugal, the described dilute acid soln containing hydrogen peroxide of residue washs, centrifugal, after merging supernatant, through rotary evaporating device concentration, then the PEFT filtering with microporous membrane of described in step 4 0.2 μm is used, last constant volume, obtain blank solution,

Step B, quantitative measurement: adopt atomic absorption spectrophotometry to carry out quantitative measurement to step 5 gained need testing solution; Be specially plumbous mensuration and adopt graphite furnace-atomic absorption, Cadmium detrmination adopts graphite furnace-atomic absorption, the mensuration of arsenic adopts hydride generation-atomic absorption photometry, and Cupper determination adopts NITRATE BY FLAME ATOMIC absorption photometry, specifically comprises following three parts:

The setting of Part I, Instrument measuring parameter:

Plumbous mensuration adopts graphite furnace-atomic absorption, and impose a condition as wavelength 283.3nm, baking temperature 110 DEG C, continues 20 seconds, ashing temperature 600 DEG C, continue 25 seconds; Atomization temperature 1800 DEG C, continues 5 seconds;

Cadmium detrmination adopts graphite furnace-atomic absorption, imposes a condition as wavelength 228.8nm, baking temperature 110 DEG C, continues 20 seconds, ashing temperature 500 DEG C, continue 25 seconds; Atomization temperature 1800 DEG C, continues 5 seconds;

The mensuration of arsenic adopts hydride generation-atomic absorption photometry, impose a condition for: adopt hydride generation system, using the sodium hydroxide solution (prepared before use) of the massfraction 0.3% containing massfraction 1% sodium borohydride as reductive agent, hydrochloric acid solution (1 → 100) is carrier fluid, nitrogen is carrier gas, and determined wavelength is 193.7nm; The sodium hydroxide solution of the described massfraction 0.3% containing massfraction 1% sodium borohydride configures before use, this hydrochloric acid solution to be commercial available quality mark be 36% hydrochloric acid carry out 100 times of dilution gained;

Cupper determination adopt flame-atomic absorption, impose a condition for: determined wavelength is 327nm, adopt Air-acetylene Flame, carry out background correction if desired;

The preparation of Part II, typical curve:

The compound method of dilution is: the dilute alkaline soln containing massfraction 10% ammonium chloride described in the step one measuring 10mL, add the dilute acid soln containing massfraction 5% hydrogen peroxide described in 20mL step 2, then with described dilute acid soln (not containing hydrogen peroxide) constant volume, dilution is obtained;

The preparation of plumbous typical curve: precision measures plumbous single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the plumbous single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate plumbous single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes the solution of every 1mL leaded 0ng, 5ng, 20ng, 40ng, 60ng, 80ng respectively; Then precision measures each concentration containing lead solution 1mL respectively, the accurate solution 0.5mL added containing massfraction 1% ammonium dihydrogen phosphate (ADP) and massfraction 0.2% magnesium nitrate respectively, after mixing, the accurate 20 μ L that draw inject graphite furnace atomizer respectively, measure absorbance, with absorbance for vertical cursor, concentration is horizontal ordinate, drawing standard curve;

The preparation of cadmium typical curve: precision measures cadmium single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the cadmium single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate cadmium single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes every 1mL respectively containing the solution of cadmium 0ng, 0.8ng, 2.0ng, 4.0ng, 6.0ng, 8.0ng; Then precision draws each concentration cadmium-containing solution 10 μ L respectively, injects graphite furnace atomizer, and measure absorbance, take absorbance as ordinate, concentration is horizontal ordinate, drawing standard curve;

The preparation of arsenic typical curve: precision measures arsenic single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the arsenic single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage, the accurate arsenic single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes every 1mL respectively containing the solution of arsenic 0ng, 5ng, 10ng, 20ng, 30ng, 40ng, then precision measures each concentration arsenic containing solution 10mL respectively, put in 25mL measuring bottle, add liquor kalii iodide (prepared before use) 1mL that massfraction is 25%, shake up, add ascorbic acid solution (prepared before use) 1mL that massfraction is 10%, shake up, scale is diluted to hydrochloric acid solution (20 → 100), this hydrochloric acid solution to be commercial available quality mark be 36% hydrochloric acid 5 times dilution gained, shake up, close plug, put in 80 DEG C of water-baths and heat 3 minutes, take out, let cool rear suction hydride generation system, measure absorption value, with peak area or absorbance for ordinate, concentration is horizontal ordinate, drawing standard curve, described massfraction be 25% liquor kalii iodide and massfraction be 10% ascorbic acid solution be and configure before use,

The preparation of copper typical curve: precision measures copper single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the copper single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate copper single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes the solution of every 1mL leaded 0 μ g, 0.05 μ g, 0.2g, 0.4 μ g, 0.6 μ g, 0.8 μ g respectively; Then get the copper-containing solution of each concentration gradient respectively, spray into flame successively, measure absorbance, take absorbance as ordinate, concentration is horizontal ordinate, drawing standard curve;

The mensuration of content of beary metal in Part III, need testing solution

Plumbous mensuration: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, record extension rate after (final concentration after dilution with survey absorbance be advisable between 0 ~ 1, this root of large-flowered skullcap sample is 2.5 times of dilutions), each precision measures 1mL, the accurate solution 0.5mL added containing massfraction 1% ammonium dihydrogen phosphate (ADP) and massfraction 0.2% magnesium nitrate respectively, mixing, accurate absorption 20 μ L, absorbance is measured with condition described in Part I, content plumbous in need testing solution is read from typical curve, calculate, to obtain final product;

Cadmium detrmination: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, record extension rate after (final concentration after dilution with survey absorbance be advisable between 0 ~ 1, this root of large-flowered skullcap sample is 2.5 times of dilutions), each precision draws 10 μ L, absorbance is measured (if test sample has interference with condition described in Part I, precision can measure standard solution respectively, blank solution and each 1mL of need testing solution, precision adds the solution 0.5mL containing massfraction 1% ammonium dihydrogen phosphate (ADP) and massfraction 0.2% magnesium nitrate, mixing, measure) in accordance with the law, the content of cadmium in need testing solution is read from typical curve, calculate, obtain,

Arsenic determination method: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, record extension rate after (final concentration after dilution with survey absorbance be advisable between 0 ~ 1, this root of large-flowered skullcap sample is 2.5 times of dilutions), each precision measures 10mL, put in 25mL measuring bottle, add liquor kalii iodide (prepared before use) 1mL that massfraction is 25%, shake up, add ascorbic acid solution (prepared before use) 1mL that massfraction is 10%, shake up, scale is diluted to hydrochloric acid solution (20 → 100), this hydrochloric acid solution to be commercial available quality mark be 36% hydrochloric acid 5 times dilution gained, shake up, close plug, put in 80 DEG C of water-baths and heat 3 minutes, take out, let cool rear suction hydride generation system, absorption value is measured with condition described in Part I, the content of arsenic in need testing solution is read from typical curve, calculate, obtain,

Copper determination method: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, record extension rate after (final concentration after dilution with survey absorbance be advisable between 0 ~ 1, this root of large-flowered skullcap sample is 2.5 times of dilutions), spray into flame successively, absorbance is measured with condition described in Part I, read the content of copper in need testing solution from typical curve, calculate, to obtain final product.

In measured baikal skullcap root decoction pieces, the content of heavy metal lead, cadmium, arsenic, copper is in table 8.

The content of heavy metal lead, cadmium, arsenic, copper in table 8 root of large-flowered skullcap

	Plumbous	Cadmium	Arsenic	Copper
					Content μ g/g (n=3)	10.38±0.07	2.08±0.02	6.07±0.02	50.71±0.20

Methodological study

(1) Linear Experiment

It is measured by the standard solution in embodiment 5 described in step B needed for method preparation Linear Experiment, take concentration as horizontal ordinate, absorbance is ordinate drawing standard curve, the results are shown in Figure 1 ~ 4.As seen from the figure, heavy metal lead, cadmium, arsenic and copper are good in 0 ~ 80ng/mL, 0 ~ 8ng/mL, 0 ~ 40ng/mL and 0 ~ 0.8 μ g/mL scope internal linear relation respectively, R ²all be more than or equal to 0.999.

(2) Precision Experiment, i.e. repeatability

The prepared slices of Chinese crude drugs that Precision Experiment adopts are the root of large-flowered skullcap, the capsule of weeping forsythia, honeysuckle, Radix Glycyrrhizae, and often kind of prepared slices of Chinese crude drugs carry out Precision Experiment respectively.

Precision takes 6 parts, the powder of the prepared slices of Chinese crude drugs, and every part of 5g measures content of beary metal wherein by flow process described in embodiment 5 respectively, the results are shown in Table 9.

Table 9 Precision Experiment

As can be seen from the table, in the root of large-flowered skullcap, the capsule of weeping forsythia, honeysuckle, Radix Glycyrrhizae, the RSD of heavy metal lead, cadmium, arsenic and copper measurement result is all less than or equal to 2%, and precision is good.

(3) accuracy experiment, i.e. the recovery

The prepared slices of Chinese crude drugs that accuracy experiment adopts are the root of large-flowered skullcap, the capsule of weeping forsythia, honeysuckle, Radix Glycyrrhizae, and often kind of Chinese medicine carries out accuracy experiment respectively.

Precision takes prepared slices of Chinese crude drugs powder 5g, add the single element solution reference material of lead, cadmium, arsenic, copper wherein, addition is divided into 3 gradients, be respectively 50% of this constituent content in sample, 100% and 200%, then carry out processing and measuring according to flow process described in embodiment 5, each concentration gradient carry out three times parallel, the results are shown in following table 10 ~ 13.

The recovery of heavy metal lead, cadmium, arsenic, copper in table 10 root of large-flowered skullcap

The recovery of heavy metal lead, cadmium, arsenic, copper in table 11 capsule of weeping forsythia

The recovery of heavy metal lead, cadmium, arsenic, copper in table 12 honeysuckle

The recovery of heavy metal lead, cadmium, arsenic, copper in table 13 Radix Glycyrrhizae

Data as can be seen from table 9 ~ 12, in often kind of prepared slices of Chinese crude drugs, the recovery of each heavy metal is all between 95 ~ 105%, and in group, the RSD of the recovery is less than or equal to 2%, and between group, the RSD of the recovery is less than or equal to 5%, and assay method accuracy is high.

(4) method contrast

The prepared slices of Chinese crude drugs that method contrast experiment adopts are the root of large-flowered skullcap, the capsule of weeping forsythia, honeysuckle, Radix Glycyrrhizae, notopterygium root, sealwort, dried orange peel, windproof, Radix Angelicae Sinensis, the rhizome of Chinese monkshood, the wind-weed, the Radix Astragali, safflower.Often kind of Chinese medicine all adopts method described in method described in the embodiment of the present invention 5 and Chinese Pharmacopoeia 2010 editions annex IXB to measure, all mensuration carry out 3 times parallel, measurement result is in table 14.

Table 14 two kinds of methods measure the comparison of heavy metal lead, cadmium, arsenic, copper in the prepared slices of Chinese crude drugs

As can be seen from the table, the inventive method measured result and Chinese Pharmacopoeia method measured result are approximate or slightly high, but RSD value is general lower than Chinese Pharmacopoeia method, thus explanation, the inventive method is better than method described in Chinese Pharmacopoeia.

Claims (7)

1. the detection method of heavy metal lead, cadmium, arsenic, copper in the prepared slices of Chinese crude drugs, is characterized in that comprising sample pretreatment and the large step of quantitative measurement two;

Described sample pretreating method is as follows:

Step one, alkaline hydrolysis: precision takes prepared slices of Chinese crude drugs powder 5g, adds the dilute alkaline soln that 10mL contains ammonium chloride, through microwave treatment after jolting, obtain alkaline hydrolysis sample solution;

Step 2, acid are carried: dilute acid soln 20mL being contained hydrogen peroxide, join rapidly under agitation in the alkaline hydrolysis sample solution of step one gained, detect pH value of solution, if pH value is greater than 2, adjust pH is to after being less than or equal to 2, carry out ultrasonic extraction, centrifugal, the dilute acid soln of residue containing hydrogen peroxide washs, centrifugal, merge supernatant, obtain crude extract; The described dilute acid soln containing hydrogen peroxide is prepared before use;

Step 3, concentrated: crude extract step 2 obtained adopts rotary evaporating device to concentrate, and obtains concentrate;

Step 4, micro-filtration: concentrate step 3 the obtained filtering with microporous membrane of 0.2 μm, obtains smart filtrate;

Step 5, constant volume: smart filtrate step 4 obtained, with dilute acid soln dilution also constant volume, obtains prepared slices of Chinese crude drugs sample solution, i.e. need testing solution;

Described method for quantitatively determining is as follows:

Steps A, prepare blank solution: measure the dilute alkaline soln containing ammonium chloride described in 10mL step one, after microwave treatment, add rapidly the dilute acid soln containing hydrogen peroxide described in 20mL step 2 under agitation, detect pH value of solution, if pH value is greater than 2, adjust pH is to after being less than or equal to 2, carry out ultrasonic process, centrifugal, the described dilute acid soln containing hydrogen peroxide of residue washs, centrifugal, after merging supernatant, through rotary evaporating device concentration, then the filtering with microporous membrane of described in step 4 0.2 μm is used, last constant volume, obtain blank solution,

Step B, quantitative measurement: adopt atomic absorption spectrophotometry to carry out quantitative measurement to step 5 gained need testing solution.

2. the detection method of heavy metal lead, cadmium, arsenic, copper in a kind of prepared slices of Chinese crude drugs according to claim 1, it is characterized in that, dilute alkaline soln described in step one is one or both in sodium hydroxide solution, potassium hydroxide solution, concentration is 0.2 ~ 1.0mol/L, and the concentration of described ammonium chloride is massfraction 10%.

3. the detection method of heavy metal lead, cadmium, arsenic, copper in a kind of prepared slices of Chinese crude drugs according to claim 1, it is characterized in that, dilute acid soln described in step 2 is one or more in salpeter solution, sulfuric acid solution, hydrochloric acid solution, citric acid solution, and concentration is more than or equal to 0.2mol/L; The concentration of described hydrogen peroxide is massfraction 5%.

4. the detection method of heavy metal lead, cadmium, arsenic, copper in a kind of prepared slices of Chinese crude drugs according to claim 1, it is characterized in that, the miillpore filter described in step 3 is PEFT material.

5. the detection method of heavy metal lead, cadmium, arsenic, copper in a kind of prepared slices of Chinese crude drugs according to claim 1, it is characterized in that, the power of microwave treatment described in step one is 800 ~ 1500W, time 30 ~ 90s, and the time of ultrasonic extraction described in described step 2 is for being more than or equal to 20min.

6. the detection method of heavy metal lead, cadmium, arsenic, copper in a kind of prepared slices of Chinese crude drugs according to claim 1, it is characterized in that, in step one, dilute alkaline soln used is sodium hydroxide solution, the concentration of sodium hydroxide solution is 0.5mol/L, microwave power is 800W, and the microwave time is 30s, and dilute acid soln described in step 2 is hydrochloric acid solution, the concentration of hydrochloric acid solution is 0.5mol/L, and described ultrasonic extraction time is 20min.

7. the detection method of heavy metal lead, cadmium, arsenic, copper in a kind of prepared slices of Chinese crude drugs according to claim 1, it is characterized in that: the employing atomic absorption spectrophotometry described in described step B respectively: plumbous mensuration adopts graphite furnace-atomic absorption, Cadmium detrmination adopts graphite furnace-atomic absorption, the mensuration of arsenic adopts hydride generation-atomic absorption photometry, and Cupper determination adopts flame-atomic absorption;

The concrete steps of atomic absorption spectrophotometry comprise following three parts:

The setting of Part I, Instrument measuring parameter:

Plumbous condition determination: wavelength 283.3nm, baking temperature 100 ~ 120 DEG C, continues 20 seconds, ashing temperature 400 ~ 750 DEG C, continues 20 ~ 25 seconds; Atomization temperature 1700 ~ 2100 DEG C, continues 4 ~ 5 seconds;

Cadmium detrmination condition: wavelength 228.8nm, baking temperature 100 ~ 120 DEG C, continues 20 seconds, ashing temperature 300 ~ 500 DEG C, continues 20 ~ 25 seconds; Atomization temperature 1500 ~ 1900 DEG C, continues 4 ~ 5 seconds;

The condition determination of arsenic: adopt hydride generation system, using the sodium hydroxide solution of the massfraction 0.3% containing massfraction 1% sodium borohydride as reductive agent, hydrochloric acid solution is carrier fluid, and nitrogen is carrier gas, and determined wavelength is 193.7nm; The sodium hydroxide solution of the described massfraction 0.3% containing massfraction 1% sodium borohydride configures before use, this hydrochloric acid solution to be commercial available quality mark be 36% hydrochloric acid carry out 100 times of dilution gained;

Cupper determination condition: determined wavelength is 327nm, adopts Air-acetylene Flame, carries out background correction if desired;

The preparation of Part II, typical curve:

The compound method of dilution is: the dilute alkaline soln containing ammonium chloride described in the step one measuring 10mL, adds the dilute acid soln containing hydrogen peroxide described in 20mL step 2, then with described dilute acid soln constant volume, obtains dilution;

The preparation of plumbous typical curve: precision measures plumbous single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the plumbous single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate plumbous single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes the solution of every 1mL leaded 0ng, 5ng, 20ng, 40ng, 60ng, 80ng respectively; Then precision measures each concentration containing lead solution 1mL respectively, the accurate solution 0.5mL added containing massfraction 1% ammonium dihydrogen phosphate (ADP) and massfraction 0.2% magnesium nitrate respectively, after mixing, the accurate 20 μ L that draw inject graphite furnace atomizer respectively, measure absorbance, with absorbance for vertical cursor, concentration is horizontal ordinate, drawing standard curve;

The preparation of cadmium typical curve: precision measures cadmium single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the cadmium single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate cadmium single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes every 1mL respectively containing the solution of cadmium 0ng, 0.8ng, 2.0ng, 4.0ng, 6.0ng, 8.0ng; Then precision draws each concentration cadmium-containing solution 10 μ L respectively, injects graphite furnace atomizer, and measure absorbance, take absorbance as ordinate, concentration is horizontal ordinate, drawing standard curve;

The preparation of arsenic typical curve: precision measures arsenic single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the arsenic single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate arsenic single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes every 1mL respectively containing the solution of arsenic 0ng, 5ng, 10ng, 20ng, 30ng, 40ng; Then precision measures each concentration arsenic containing solution 10mL respectively, put in 25mL measuring bottle, add the liquor kalii iodide 1mL that massfraction is 25%, shake up, add the ascorbic acid solution 1mL that massfraction is 10%, shake up, be diluted to scale with hydrochloric acid solution, this hydrochloric acid solution to be commercial available quality mark be 36% hydrochloric acid 5 times dilution gained, shake up, close plug, put in 80 DEG C of water-baths and heat 3 minutes, take out, let cool rear suction hydride generation system, measure absorption value, with peak area or absorbance for ordinate, concentration is horizontal ordinate, drawing standard curve; Described massfraction be 25% liquor kalii iodide and massfraction be 10% ascorbic acid solution be and configure before use;

The preparation of copper typical curve: precision measures copper single element solution reference material, respectively by described diluted and constant volume, makes every 1mL containing after the copper single element Standard Stock solutions of 10 μ g, in 0 ~ 5 DEG C of storage; The accurate copper single element Standard Stock solutions measuring 6 gradient amounts respectively, respectively by described diluted and constant volume, makes the solution of every 1mL leaded 0 μ g, 0.05 μ g, 0.2g, 0.4 μ g, 0.6 μ g, 0.8 μ g respectively; Then get the copper-containing solution of each concentration gradient respectively, spray into flame successively, measure absorbance, take absorbance as ordinate, concentration is horizontal ordinate, drawing standard curve;

The mensuration of content of beary metal in Part III, need testing solution:

Plumbous mensuration: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, after record extension rate, each precision measures 1mL, the accurate solution 0.5mL added containing massfraction 1% ammonium dihydrogen phosphate (ADP) and massfraction 0.2% magnesium nitrate respectively, mixing, accurate absorption 20 μ L, absorbance is measured with condition described in Part I, read content plumbous in need testing solution from typical curve, calculate, to obtain final product;

Cadmium detrmination: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, after record extension rate, each precision draws 10 μ L, absorbance is measured with condition described in Part I, read the content of cadmium in need testing solution from typical curve, calculate, to obtain final product;

Arsenic determination method: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, after record extension rate, each precision measures 10mL, put in 25mL measuring bottle, add the liquor kalii iodide 1mL that massfraction is 25%, shake up, add the ascorbic acid solution 1mL that massfraction is 10%, shake up, scale is diluted to hydrochloric acid solution, this hydrochloric acid solution to be commercial available quality mark be 36% hydrochloric acid 5 times dilution gained, shake up, close plug, put in 80 DEG C of water-baths and heat 3 minutes, take out, let cool rear suction hydride generation system, absorption value is measured with condition described in Part I, the content of arsenic in need testing solution is read from typical curve, calculate, obtain, described massfraction be 25% liquor kalii iodide and massfraction be 10% ascorbic acid solution be and configure before use,

Copper determination method: the need testing solution of the blank solution of steps A gained and step 5 gained is carried out precision and dilutes, after record extension rate, sprays into flame successively, absorbance is measured with condition described in Part I, read the content of copper in need testing solution from typical curve, calculate, to obtain final product.