CN104729895B - Freeze the pre-treating method of harmful substance in zone refining extraction milk sample product - Google Patents
Freeze the pre-treating method of harmful substance in zone refining extraction milk sample product Download PDFInfo
- Publication number
- CN104729895B CN104729895B CN201410852780.2A CN201410852780A CN104729895B CN 104729895 B CN104729895 B CN 104729895B CN 201410852780 A CN201410852780 A CN 201410852780A CN 104729895 B CN104729895 B CN 104729895B
- Authority
- CN
- China
- Prior art keywords
- kettle
- extraction
- high pressure
- kettle cover
- freezing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Dairy Products (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
The present invention relates to a kind of pre-treating method of harmful substance in milk powder sample, more particularly to a kind of pre-treating method for freezing harmful substance in zone refining extraction milk sample product, it is mainly used in being measured chloramphenicol drug residue in milk power for infant and young children, belongs to food processing detection field.This method comprises the following steps：(1) solid milk powder sample, plus ultra-pure water are weighed, or weighs samples of latex, and the mixing of organic extracts reagent, is first extracted, then is vibrated, treatment fluid is obtained；(2) treatment fluid is poured into high pressure freezing extraction kettle, injects ethyl acetate；(3) high pressure freezing extraction kettle is put into refrigerator freezing, or is put into ice bath；(4) high pressure freezing extraction kettle is taken out, upper organic phase is drawn, filtering obtains filtrate.Not only extraction efficiency is high for the pre-treating method of harmful substance in freezing zone refining extraction milk sample product provided by the present invention, can reduce or even eliminate interfering component, and simple to operate, contributes to the effective detection of harmful substance in milk sample product.
Description
Technical field
The present invention relates to a kind of pre-treating method of harmful substance in milk powder sample, more particularly to a kind of freezing zone refining
The pre-treating method of harmful substance in milk sample product is extracted, is mainly used in entering chloramphenicol drug residue in milk power for infant and young children
Row is determined, and belongs to food processing detection field.
Background technology
Chloramphenicol (chloramphenicol, CAP) is a kind of high-efficiency broad spectrum antibiotic, is usually used in the various infectiousness of animal
A variety of pathogens are had stronger inhibitory action by the treatment of disease.Because chloramphenicol is cheap, disease resistance is strong, non-to milk cow
The situation of canonical chloramphenicol happens occasionally, so that can have residual chloromycetin in milk powder, so that the health care belt to infant comes
It is potentially hazardous.Chloramphenicol is classified as legal disabling veterinary drug by current European Union, the U.S..European Union determines that minimum limitation is 0.1 μ g/
Kg, China also provides animality " must not detect ".
Sample pre-treatments are to detect the committed step of chloramphenicol residue in milk powder, directly affect the result of detection.Milk powder
Middle sample pre-treatments are to set up the premise of fast and accurately analysis method.For the sample of different substrates, and in order to different
Analysis purpose, at present, a variety of efficient Sample Pretreatment Technique Useds, such as：Liquid-liquid extraction, mutually extraction, matrix solid phase dispersion extraction,
SPME, Stir Bar Sorptive Extraction, membrane extraction, liquid-phase micro-extraction, supercritical fluid extraction, accelerated solvent extraction, molecule
The technologies such as trace, microwave auxiliary extraction have been widely used in food middle peasant, residue of veterinary drug, poisonous and harmful substance residual and eaten
The pre-treatment of the residue detections such as product additive.However, these pretreatment modes generally require to consume substantial amounts of organic solvent, it is corresponding
Fiber material and corresponding pre-treatment instrument, not only increase analysis cost, and secondary pollution can be caused.
The content of the invention
It is an object of the invention to provide a kind of pre-treating method for freezing harmful substance in zone refining extraction milk sample product,
Not only extraction efficiency is high for the pre-treating method of harmful substance in freezing zone refining extraction milk sample product provided by the present invention, can
Reduce and even eliminate interfering component, and it is simple to operate, contribute to the effective detection of harmful substance in milk sample product.
Technical solution of the present invention is as follows：
A kind of pre-treating method for freezing harmful substance in zone refining extraction milk sample product,
Raw material used in this method includes：
Concentration is 100mg/l deuterated chloramphenicol internal standard-d5 standard items,
Purity is the saturation ethyl acetate of chromatographically pure,
Ultra-pure water,
Milk sample product, the milk sample product are solid milk powder sample or samples of latex；
Equipment used in this method includes
100mL high pressures freeze extraction kettle,
Refrigerator-freezer,
Display precise thermometer；
The step of this method includes carrying out successively as follows：
(1) solid milk powder 5~10g of sample is weighed, solid milk powder sample is added into 50~80mL of ultra-pure water, and for extracting breast
Organic 20~50mL of extracts reagent mixing of harmful substance in sample, first 1~5min of extraction of ocean eddies, then middling speed vibrate 2~5min,
Obtain treatment fluid；Or 50~80mL of samples of latex is weighed, and the organic extraction satisfied for extracting harmful substance in milk sample product is tried
20~50mL of agent is mixed, first 1~5min of extraction of ocean eddies, then middling speed vibrates 2~5min, obtains treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and firmly tightened, high pressure freezing extraction kettle is put into -18~-22
DEG C refrigerator in freeze 1.8-2.2h, or be put into 25-35min in ice bath；
(4) sealing bolt on kettle cover is opened after taking-up high pressure freezing extraction kettle, elder generation, then opens kettle cover, is inhaled with suction pipe
5~20ml upper organic phases are taken, using 0.20-0.24 μm of membrane filtration, the filtrate for detection are obtained.
Further,
The organic extracts reagent for being used to extract harmful substance in milk sample product is saturation ethyl acetate.
Further, concentration is such as needed,
Organic phase is first pipetted into centrifuge tube before filtration described in the step of this method (4), and nitrogen blows at 45-55 DEG C
It is dry, refiltered after then flowing phased soln with 0.8-1.2mL.
The inventive principle of the present invention is as follows：
For the aqueous solution containing target solute, when temperature is reduced to its freezing point, water, which starts to freeze, separates out solid phase.Solute
Different solubility in ice phase and aqueous phase, its concentration in different phases is maintained according to the limitation of chemical potential or the equilibrium constant.Its
General principle is shown in Figure 1.
Concentration of the solute in aqueous phase is CL, the concentration in ice is CS.In the case where temperature and pressure keeps constant,
Its distribution coefficient k in solid-liquid biphase equilibrium is invariable：
When gradually being build-up ice with dampening, although it is considered that the solute concentration in the aqueous solution is equal everywhere, in ice
Solute concentration is not homogeneous.When there is dVsLiquid freezing become solid, and wherein the amount of solute is dnsIt is during mol, then small at this
The concentration of solute is in block solid：
Convolution (1)-(2), are arranged：
Wherein, VL、nLRespectively liquid phase volume and the wherein concentration of solute.
The concentration of solute is C in the aqueous solution when starting not freeze0；Volume is V0；Two-phase density ratio is a, then
VS+aVS=V0 (4)
ns+nL=c0V0 (5)
Formula (4) and formula (5) are substituted into formula (3), integration can be obtained：
Formula (6) is reflected during the sample pretreatment carried out using zone refining in the aqueous solution, solute concentration in aqueous phase
Change.Obviously, concentration of the solute in aqueous phase is relevant in the volume fraction of the two alternate equilibrium constants and its ice with it.
The pre-treating method of harmful substance is existed using water in freezing zone refining extraction milk sample product provided by the present invention
Icing volumetric expansion produces the principle of high pressure in closed container, with reference to freezing zone refining and liquid-liquid extraction techniques, is developed
A kind of high pressure freezing liquid-liquid extraction techniques freezes liquid-liquid extraction by high pressure, can reduce or even eliminate some interfering components, and
Some characteristic components can be significantly improved with concentration effect, and some can not be detected in normal temperature and freezing liquid-liquid extraction
Trace components, is substantially enriched with, therefore can be used as a kind of new sample pre-treatments skill in high pressure freezing liquid-liquid extraction
Art is used widely in field of food detection.Prior art is contrasted, the present invention has the following advantages：
1) extraction efficiency is high.
2) it can reduce or even eliminate interfering component.
3) it is simple to operate.
4) the Milk Powder Formula For Infants acetonitrile and first alcohol and water of most of complicated components dissolve each other in the prior art, high pressure freezing
After can not be layered very well, cause extraction efficiency low, and saturation ethyl acetate can and water stratification, high pressure freezing after aqueous phase solidify,
Chloramphenicol is dissolved in saturation ethyl acetate, and extraction efficiency is high.
Brief description of the drawings
Fig. 1 extracts the general principle figure of the pre-treating method of harmful substance in milk sample product for present invention freezing zone refining.
Embodiment
With reference to embodiment and specific embodiment, the present invention will be described in detail.
Embodiment is as follows：
(1) solid milk powder 5~10g of sample is weighed, solid milk powder sample is added into 50~80mL of ultra-pure water, and saturation acetic acid second
20~50mL of ester is mixed, first 1~5min of extraction of ocean eddies, then middling speed vibrates 2~5min, obtains treatment fluid；Or weigh emulsion sample
50~80mL of product and 20~50mL of saturation ethyl acetate mixing, first 1~5min of extraction of ocean eddies, then middling speed vibrate 2~5min, obtained
Treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and firmly tightened, high pressure freezing extraction kettle is put into -18~-22
DEG C refrigerator in freeze 1.8-2.2h, or be put into 25-35min in ice bath；
(4) sealing bolt on kettle cover is opened after taking-up high pressure freezing extraction kettle, elder generation, then opens kettle cover, is inhaled with suction pipe
5~20ml upper organic phases are taken, using 0.20-0.24 μm of membrane filtration, the filtrate for detection are obtained.
Organic phase will such as be concentrated described in step (4), can be pipetted before filtration into centrifuge tube and the nitrogen at 45-55 DEG C
Drying, is refiltered with 0.8-1.2mL flowing phased solns.
(2) embodiment is as follows：The present invention is further illustrated below by embodiment：
Embodiment group one (solid milk powder sample, without concentration)
Embodiment 1-1
(1) solid milk powder sample 8g is weighed, adds ultra-pure water 65mL, and saturation ethyl acetate 35mL to mix in solid milk powder sample
Close, first extraction of ocean eddies 3min, then middling speed vibration 3min, obtain treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -20 DEG C
Middle freezing 2h, or it is put into 30min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 10ml with suction pipe
Upper organic phase, using 0.22 μm of membrane filtration, obtains the filtrate for detection.
Embodiment 1-2
(1) solid milk powder sample 5g is weighed, adds ultra-pure water 50mL, and saturation ethyl acetate 20mL to mix in solid milk powder sample
Close, first extraction of ocean eddies 1min, then middling speed vibration 2min, obtain treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -18 DEG C
Middle freezing 1.8h, or it is put into 25min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 5ml with suction pipe
Upper organic phase, using 0.20 μm of membrane filtration, obtains the filtrate for detection.
Embodiment 1-3
(1) solid milk powder sample 10g is weighed, solid milk powder sample is added into ultra-pure water 80mL, and saturation ethyl acetate 50mL
Mixing, first extraction of ocean eddies 5min, then middling speed vibration 5min, obtain treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -22 DEG C
Middle freezing 2.2h, or it is put into 35min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 20ml with suction pipe
Upper organic phase, using 0.24 μm of membrane filtration, obtains the filtrate for detection.
Embodiment 1-4
(1) solid milk powder sample 5g is weighed, adds ultra-pure water 50mL, and saturation ethyl acetate 20mL to mix in solid milk powder sample
Close, first extraction of ocean eddies 5min, then middling speed vibration 2min, obtain treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -22 DEG C
Middle freezing 1.8h, or it is put into 35min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 5ml with suction pipe
Upper organic phase, using 0.24 μm of membrane filtration, obtains the filtrate for detection.
Embodiment 1-5
(1) solid milk powder sample 10g is weighed, solid milk powder sample is added into ultra-pure water 80mL, and saturation ethyl acetate 50mL
Mixing, first extraction of ocean eddies 1min, then middling speed vibration 5min, obtain treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -18 DEG C
Middle freezing 2.2h, or it is put into 25min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 20ml with suction pipe
Upper organic phase, using 0.20 μm of membrane filtration, obtains the filtrate for detection.
Embodiment group two (solid milk powder sample needs concentration)
Embodiment 2-1
(1) solid milk powder sample 8g is weighed, adds ultra-pure water 65mL, and saturation ethyl acetate 35mL to mix in solid milk powder sample
Close, first extraction of ocean eddies 3min, then middling speed vibration 3min, obtain treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -20 DEG C
Middle freezing 2h, or it is put into 30min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 10ml with suction pipe
Upper organic phase, is pipetted into centrifuge tube and nitrogen is dried up at 50 DEG C, phased soln is flowed with 1mL, using 0.22 μm of filter membrane mistake
Filter, obtains the filtrate for detection.
Embodiment 2-2
(1) solid milk powder sample 5g is weighed, adds ultra-pure water 50mL, and saturation ethyl acetate 50mL to mix in solid milk powder sample
Close, first extraction of ocean eddies 1min, then middling speed vibration 2min, obtain treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -20 DEG C
Middle freezing 2h；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 10ml with suction pipe
Upper organic phase, is pipetted into centrifuge tube and nitrogen is dried up at 50 DEG C, phased soln is flowed with 1mL, using 0.22 μm of filter membrane mistake
Filter, obtains the filtrate for detection.
Embodiment 2-3
(1) solid milk powder sample 10g is weighed, solid milk powder sample is added into ultra-pure water 80mL, and saturation ethyl acetate 50mL
Mixing, first extraction of ocean eddies 5min, then middling speed vibration 5min, obtain treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -22 DEG C
Middle freezing 2.2h, or it is put into 35min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 20ml with suction pipe
Upper organic phase, is pipetted into centrifuge tube and nitrogen is dried up at 55 DEG C, phased soln is flowed with 1.2mL, using 0.24 μm of filter membrane
Filtering, obtains the filtrate for detection.
Embodiment 2-4
(1) solid milk powder sample 5g is weighed, adds ultra-pure water 50mL, and saturation ethyl acetate 20mL to mix in solid milk powder sample
Close, first extraction of ocean eddies 5min, then middling speed vibration 2min, obtain treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -22 DEG C
Middle freezing 1.8h, or it is put into 35min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 5ml with suction pipe
Upper organic phase, is pipetted into centrifuge tube and nitrogen is dried up at 45 DEG C, phased soln is flowed with 1.2mL, using 0.24 μm of filter membrane
Filtering, obtains the filtrate for detection.
Embodiment 2-5
(1) solid milk powder sample 10g is weighed, solid milk powder sample is added into ultra-pure water 80mL, and saturation ethyl acetate 50mL
Mixing, first extraction of ocean eddies 1min, then middling speed vibration 5min, obtain treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is reinjected with syringe by the aperture in kettle cover into high pressure freezing extraction kettle suitable
Saturation ethyl acetate is measured, high pressure is freezed to the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -18 DEG C
Middle freezing 2.2h, or it is put into 25min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 20ml with suction pipe
Upper organic phase, is pipetted into centrifuge tube and nitrogen is dried up at 55 DEG C, phased soln is flowed with 0.8mL, using 0.20 μm of filter membrane
Filtering, obtains the filtrate for detection.
Embodiment group three (samples of latex, without concentration)
Embodiment 3-1
(1) samples of latex 65mL and saturation ethyl acetate 35mL mixing, first extraction of ocean eddies 3min, then middling speed vibration are weighed
3min, obtains treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -20 DEG C
Middle freezing 2h, or it is put into 30min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 10ml with suction pipe
Upper organic phase, using 0.22 μm of membrane filtration, obtains the filtrate for detection.
Embodiment 3-2
(1) samples of latex 65mL and saturation ethyl acetate 20mL mixing, first extraction of ocean eddies 1min, then middling speed vibration are weighed
2min, obtains treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -18 DEG C
Middle freezing 1.8h, or it is put into 25min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 5ml with suction pipe
Upper organic phase, using 0.20 μm of membrane filtration, obtains the filtrate for detection.
Embodiment 3-3
(1) samples of latex 65mL and saturation ethyl acetate 50mL mixing, first extraction of ocean eddies 5min, then middling speed vibration are weighed
5min, obtains treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle
Lid, opens the sealing bolt on kettle cover, is freezed and reinjected in extraction kettle to high pressure by the aperture in kettle cover with syringe afterwards
Appropriate saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -22 DEG C
Middle freezing 2.2h, or it is put into 35min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 20ml with suction pipe
Upper organic phase, using 0.24 μm of membrane filtration, obtains the filtrate for detection.
Embodiment 3-4
(1) samples of latex 65mL and saturation ethyl acetate 20mL mixing, first extraction of ocean eddies 5min, then middling speed vibration are weighed
2min, obtains treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -22 DEG C
Middle freezing 1.8h, or it is put into 35min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 5ml with suction pipe
Upper organic phase, using 0.24 μm of membrane filtration, obtains the filtrate for detection.
Embodiment 3-5
(1) samples of latex 65mL and saturation ethyl acetate 50mL mixing, first extraction of ocean eddies 1min, then middling speed vibration are weighed
5min, obtains treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -18 DEG C
Middle freezing 2.2h, or it is put into 25min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 20ml with suction pipe
Upper organic phase, using 0.20 μm of membrane filtration, obtains the filtrate for detection.
Embodiment group four (samples of latex needs concentration)
Embodiment 4-1
(1) samples of latex 65mL and saturation ethyl acetate 35mL mixing, first extraction of ocean eddies 3min, then middling speed vibration are weighed
3min, obtains treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle
Lid, opens the sealing bolt on kettle cover, is freezed and reinjected in extraction kettle to high pressure by the aperture in kettle cover with syringe afterwards
Appropriate saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -20 DEG C
Middle freezing 2h, or it is put into 30min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 10ml with suction pipe
Upper organic phase, is pipetted into centrifuge tube and nitrogen is dried up at 50 DEG C, phased soln is flowed with 1mL, using 0.22 μm of filter membrane mistake
Filter, obtains the filtrate for detection.
Embodiment 4-2
(1) samples of latex 65mL and saturation ethyl acetate 20mL mixing, first extraction of ocean eddies 1min, then middling speed vibration are weighed
2min, obtains treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -18 DEG C
Middle freezing 1.8h, or it is put into 25min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 5ml with suction pipe
Upper organic phase, is pipetted into centrifuge tube and nitrogen is dried up at 45 DEG C, phased soln is flowed with 0.8mL, using 0.20 μm of filter membrane
Filtering, obtains the filtrate for detection.
Embodiment 4-3
(1) samples of latex 65mL and saturation ethyl acetate 50mL mixing, first extraction of ocean eddies 5min, then middling speed vibration are weighed
5min, obtains treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -22 DEG C
Middle freezing 2.2h, or it is put into 35min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 20ml with suction pipe
Upper organic phase, is pipetted into centrifuge tube and nitrogen is dried up at 55 DEG C, phased soln is flowed with 1.2mL, using 0.24 μm of filter membrane
Filtering, obtains the filtrate for detection.
Embodiment 4-4
(1) samples of latex 65mL and saturation ethyl acetate 20mL mixing, first extraction of ocean eddies 5min, then middling speed vibration are weighed
2min, obtains treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -22 DEG C
Middle freezing 1.8h, or it is put into 35min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 5ml with suction pipe
Upper organic phase, is pipetted into centrifuge tube and nitrogen is dried up at 45 DEG C, phased soln is flowed with 1.2mL, using 0.24 μm of filter membrane
Filtering, obtains the filtrate for detection.
Embodiment 4-5
(1) samples of latex 65mL and saturation ethyl acetate 50mL mixing, first extraction of ocean eddies 1min, then middling speed vibration are weighed
5min, obtains treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover,
The sealing bolt on kettle cover is opened afterwards, is freezed and is reinjected in extraction kettle in right amount to high pressure by the aperture in kettle cover with syringe
Saturation ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and tightened, high pressure is freezed into the refrigerator that extraction kettle is put into -18 DEG C
Middle freezing 2.2h, or it is put into 25min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, kettle cover is opened and draws 20ml with suction pipe
Upper organic phase, is pipetted into centrifuge tube and nitrogen is dried up at 55 DEG C, phased soln is flowed with 0.8mL, using 0.20 μm of filter membrane
Filtering, obtains the filtrate for detection.
In various embodiments above：
Used raw material includes：
Concentration is 100mg/l deuterated chloramphenicol internal standard-d5 standard items,
Purity is the saturation ethyl acetate of chromatographically pure,
Ultra-pure water,
Used equipment includes
100mL high pressures freeze extraction kettle,
Refrigerator-freezer,
Display precise thermometer；
The organic phase that the pre-treating method of harmful substance is obtained in the freezing zone refining extraction milk sample product of the present invention is adopted
Chloramphenicol residue in milk power for infant and young children is determined with high performance liquid chromatography tandem mass spectrum method, experimental data is as follows：
High performance liquid chromatography tandem mass spectrum method determines chloramphenicol residue experiment content in milk power for infant and young children
1st, the reagent and material that experiment is used
Chloramphenicol standard items (Sigma, purity 99%)
Chloramphenicol d5 internal standards standard items (Cambridge Isotope Laboratories, Inc. purity 98%) ultra-pure water
Solid-phase extraction column (the ㏄ of Waters Oasis HLB 3 are prepared by Millipore pure water systems (Millipore companies of the U.S.)
60mg) organic solvent is chromatographically pure
2nd, the preparation of storing solution
Each 100mg of CAP, d5-CAP standard items is weighed, is dissolved with 100mL methanol, 1mg/mL storing solutions is made, 4 are stored in
In DEG C refrigerator.Simultaneously compound concentration be respectively 2.5,1,0.5,0.25, the standard system that 0.1ng/mL internal standards concentration is 2.5ng/mL
Row, draw standard curve.
3rd, the instrument that experiment is used
Liquid chromatography-tandem mass spectrometry instrument：Agilent 6410B types series connection triple quadrupole bar mass spectrum, with Agilent1200 types
Liquid chromatograph (U.S.'s Agilent), Millipore pure water systems (U.S. Mi Libo),
Solid-phase extraction device (24 hole), high pressure freezing extraction kettle (stainless steel, can high pressure resistant and low temperature, and can be square
Just open and have the device for preventing explosion), centrifuge (Jiangsu Xiang Yi companies), nitrogen evaporator (all directions century), Rotary Evaporators
(Shanghai is sub- flourish), refrigerator-freezer (Haier) display precise thermometer (Taiwan Thailand bodyguard).
4th, analysis condition
4.1 chromatographic condition
Chromatographic column Waters ACQUITY UPLC BEHC181.7 μm 2.1 × 50mm flow velocitys：0.3mL/min；Column temperature：35
℃；Sample size：10μL；Mobile phase：1 ‰ formic acid+acetonitrile (70：30, volume ratio).
4.2 Mass Spectrometry Conditions
Ion gun:Electric spray ion source (ESI)；Scan mode：Anion is scanned；Capillary voltage -4000V；Detection side
Formula：Many reaction detections；Dry gas：N2；Collide atmospheric pressure：40Psi；Dry temperature degree 340；Dry gas stream speed：10L/min；
The conditional parameter of the chloramphenicol mass spectral analysis of table 1
Experimental method
Three kinds of different pre-treating methods compare experiment
Contrast experiment's 1- liquid-liquid extraction methods
Weigh powdered milk sample (2 ± 0.05) g to be placed in tool plug centrifuge tube, the deuterated chloramphenicol internal standard for adding 25ng/mL is molten
The μ L of liquid 200, plus ethyl acetate 10mL and saturated nacl aqueous solution 10mL, vortex 1min, then middling speed vibration 2min, in 10000r/
Min centrifuges 2min, takes supernatant into another centrifuge tube, repeats to extract 1 time, merges supernatant.N-hexane is added in extract solution
8mL, vortex oscillation 2min, centrifuge 5min in 8000r/min, abandon supernatant, subnatant is transferred in pear shape bottle, in 50 DEG C
Rotary evaporated to dryness, is dissolved, 0.22 μm of membrane filtration with mobile phase 2mL, obtains upper machine testing after the filtrate for detection.
Contrast experiment's 2- solid phase extractions
Weigh powdered milk sample (2 ± 0.05) g to be placed in tool plug centrifuge tube, the deuterated chloramphenicol internal standard for adding 25ng/mL is molten
The μ L of liquid 200, plus ethyl acetate 10mL and saturated nacl aqueous solution 10mL, vortex 1min, then middling speed vibration 2min, in 10000r/
Min centrifuges 2min, takes supernatant into another centrifuge tube, repeats to extract 1 time, merges supernatant.N-hexane is added in extract solution
8mL, vortex oscillation 2min, 5min is centrifuged in 8000r/min, abandons supernatant by subnatant is transferred in pear shape bottle, in 50 DEG C
Rotary evaporated to dryness, with the methanol (95 of water one：5) 3mL dissolves, and solid-phase extraction column uses methanol 3mL successively, and water 3mL activation takes standby
Liquid all crosses post, then uses 3mL water washings successively, and decompressing and extracting is finally eluted with 3mL methanol, collects eluent, and at 50 DEG C
Nitrogen is dried up, and phased soln is flowed with 1mL, and 0.22 μm of membrane filtration obtains upper machine testing after the filtrate for detection.
The freezing zone refining extraction (embodiment 2-2) that the present invention is used
Powdered milk sample (5 ± 0.05) g is weighed, is placed in 250ml Erlenmeyer flasks and adds 25ng/ deuterated chloramphenicol inner mark solution
500 μ L, plus ultra-pure water 50mL and saturation ethyl acetate 50mL, vortex 1min, then middling speed vibration 2min.It is cold that treatment fluid pours into high pressure
Freeze in extraction kettle, cover tightly kettle cover, and kettle kettle cover is tightened with corresponding spanner, the sealing bolt on kettle cover is opened afterwards, with note
Emitter is freezed in extraction kettle to high pressure by the aperture in kettle cover and reinjects few ethyl acetate, to ensure gas is not present in device
Bubble.Sealing bolt on kettle cover is screwed in into kettle cover, and screwed up with a wrench.High pressure freezing extraction kettle is put into -20 DEG C of refrigerator
2h is freezed, high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened afterwards, it is organic that opening kettle cover draws upper strata with suction pipe
Phase is simultaneously filtered, and is pipetted 10ml organic phases nitrogen into centrifuge tube and at 50 DEG C and is dried up, phased soln, 0.22 μm of filter are flowed with 1mL
Membrane filtration, obtains upper machine testing after the filtrate for detection.
Control experiment scheme
The powdered milk sample 5 containing chloramphenicol is taken to be tested, experiment, does 5 mark-ons every time every time, totally 5 experiments.
The Comparative result of three kinds of different pre-treating methods
The Comparative result of 2 three kinds of different pre-treating methods of table
The rate of recovery contrast of three kinds of different pre-treating methods
The rate of recovery contrast of 3 three kinds of different pre-treating methods of table
The rate of recovery and Precision Experiment of the freezing zone refining extraction that the present invention is used for different samples
The rate of recovery and Precision Experiment of the different samples of table 4
From table 4 this it appears that the rate of recovery of the chloramphenicol in fluid milk matrix is between 98%-104%, relative mark
Quasi- deviation RSD is between 1.23%-3.89%；The rate of recovery of the chloramphenicol in milk powder matrix is between 95%-105%, relatively
Standard deviation RSD is between 2.87%-5.21%.
The deuterated chloramphenicol internal standard response contrast of three kinds of different pre-treating methods
The deuterated chloramphenicol internal standard response contrast of 5 three kinds of different pre-treating methods of table
Experiment shows that the sample pre-treatments of this method are simple and easy to apply in summary, and analysis is quick, can be baby formula breast
The supervision of banned substance provides technical basis with supervision in powder
Simply technical scheme is explained in detail for above-mentioned embodiment, the present invention not only only office
It is limited to above-described embodiment, every any improvement or replacement according to the principle of the invention all should be within protection scope of the present invention.
Claims (3)
1. a kind of pre-treating method for freezing harmful substance in zone refining extraction milk sample product, it is characterised in that：
The step of this method includes carrying out successively as follows：
(1) solid milk powder 5~10g of sample is weighed, solid milk powder sample is added into 50~80mL of ultra-pure water, and for extracting milk sample product
Organic 20~50mL of extracts reagent mixing of middle harmful substance, first 1~5min of extraction of ocean eddies, then middling speed vibrate 2~5min, obtained
Treatment fluid；Or weigh 50~80mL of samples of latex, and for extract organic extracts reagent 20 of harmful substance in milk sample product~
50mL is mixed, first 1~5min of extraction of ocean eddies, then middling speed vibrates 2~5min, obtains treatment fluid；
(2) treatment fluid obtained by step (1) is poured into high pressure freezing extraction kettle, covers tightly kettle cover, and tighten kettle kettle cover, afterwards
The sealing bolt on kettle cover is opened, is freezed with syringe by the aperture in kettle cover to high pressure in extraction kettle and reinjects appropriate saturation
Ethyl acetate, high pressure is freezed the bubble remained in extraction kettle and discharged；
(3) sealing bolt on kettle cover is screwed in into kettle cover, and firmly tightened, high pressure freezing extraction kettle is put into -18~-22 DEG C
1.8-2.2h is freezed in refrigerator, or is put into 25-35min in ice bath；
(4) high pressure freezing extraction kettle is taken out, the sealing bolt on kettle cover is opened after elder generation, then opens kettle cover, 5 are drawn with suction pipe~
20ml upper organic phases, using 0.20-0.24 μm of membrane filtration, obtain the filtrate for detection.
2. the pre-treating method of harmful substance, its feature in freezing zone refining extraction milk sample product according to claim 1
It is：The organic extracts reagent for being used to extract harmful substance in milk sample product is saturation ethyl acetate.
3. the pre-treating method of harmful substance in freezing zone refining extraction milk sample product according to claim 1 or 2, it is special
Levy and be：Organic phase is first pipetted into centrifuge tube before filtration described in the step of this method (4), and nitrogen blows at 45-55 DEG C
It is dry, refiltered after then flowing phased soln with 0.8-1.2mL.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410852780.2A CN104729895B (en) | 2014-12-31 | 2014-12-31 | Freeze the pre-treating method of harmful substance in zone refining extraction milk sample product |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410852780.2A CN104729895B (en) | 2014-12-31 | 2014-12-31 | Freeze the pre-treating method of harmful substance in zone refining extraction milk sample product |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104729895A CN104729895A (en) | 2015-06-24 |
| CN104729895B true CN104729895B (en) | 2017-09-12 |
Family
ID=53453993
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410852780.2A Active CN104729895B (en) | 2014-12-31 | 2014-12-31 | Freeze the pre-treating method of harmful substance in zone refining extraction milk sample product |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104729895B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111929388B (en) * | 2020-09-09 | 2021-04-06 | 广州检验检测认证集团有限公司 | Extraction method, detection method and extraction device for flavors and fragrances in food |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102901778A (en) * | 2011-07-29 | 2013-01-30 | 内蒙古蒙牛乳业（集团）股份有限公司 | Pretreatment method for detecting chloramphenicol in milk or mild products and method for detecting chloramphenicol in milk or mild products |
| CN103336064A (en) * | 2012-07-17 | 2013-10-02 | 江西出入境检验检疫局检验检疫综合技术中心 | A liquid chromatogram-mass spectrum/mass spectrum (LC-MS/MS) determination method for chloramphenicol residue amount in milk powder |
| CN203711360U (en) * | 2013-12-16 | 2014-07-16 | 明一国际营养品集团有限公司 | Device for removing impurities before packaging milk powder |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013253790A (en) * | 2012-06-05 | 2013-12-19 | Chube Univ | Analytical method of nivalenol |
-
2014
- 2014-12-31 CN CN201410852780.2A patent/CN104729895B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102901778A (en) * | 2011-07-29 | 2013-01-30 | 内蒙古蒙牛乳业（集团）股份有限公司 | Pretreatment method for detecting chloramphenicol in milk or mild products and method for detecting chloramphenicol in milk or mild products |
| CN103336064A (en) * | 2012-07-17 | 2013-10-02 | 江西出入境检验检疫局检验检疫综合技术中心 | A liquid chromatogram-mass spectrum/mass spectrum (LC-MS/MS) determination method for chloramphenicol residue amount in milk powder |
| CN203711360U (en) * | 2013-12-16 | 2014-07-16 | 明一国际营养品集团有限公司 | Device for removing impurities before packaging milk powder |
Non-Patent Citations (1)
| Title |
|---|
| 《胶体金免疫层析法检测蜂蜜中氯霉素残留的前处理方法研究》;王元凤等;《食品科学》;20091231;第30卷(第08期);第267-268页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104729895A (en) | 2015-06-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104535664B (en) | A kind of method simultaneously detecting multiple mycotoxin in sesame paste | |
| Nord et al. | Sample preconcentration by continuous flow extraction with a flow injection atomic absorption detection system | |
| CN101718753B (en) | Ion chromatography single-pump column switching system | |
| CN104215704B (en) | The method for quick of oligosaccharides in adulterated honey | |
| CN103901129A (en) | Method for detecting ten types of organophosphorus pesticides by using magnetic separation-gas chromatography | |
| CN107677757A (en) | The method for determining vanillic aldehyde in food, methyl vanillin, Ethyl vanillin simultaneously | |
| CN103278594B (en) | Universal rapid detection method for micromolecule poisonous and harmful materials in powdery food | |
| CN105424845A (en) | Method for analyzing aroma components of flavoring material through GC/MS based on thermal desorption | |
| CN109061016A (en) | A kind of preparation method and application of the solid-phase extraction column of enriched biological amine | |
| CN103713066B (en) | Method for extracting and detecting vanillin, methyl vanillin, ethyl vanillin and coumarin in milk powder | |
| CN104193875B (en) | The preparation method of stilboestrol magnetic molecularly imprinted polymer and application thereof | |
| CN110208401A (en) | Solid phase is dehydrated extraction-supercritical fluid chromatography-mass spectrum on-line analysis system and method | |
| CN104729895B (en) | Freeze the pre-treating method of harmful substance in zone refining extraction milk sample product | |
| CN106645460A (en) | Method for quickly and accurately determining sulfite, sulfate and thiosulfate anion in biogas slurry | |
| CN105911191A (en) | Simultaneous extraction and purification method of four types of mycotoxin in rice | |
| CN110412169A (en) | The on-line solid phase extraction gaschromatographic mass spectrometry detection method of organotin in marine sediment | |
| CN109828051A (en) | A kind of detection method of toxic compounds | |
| CN106645539B (en) | A kind of method of ultra performance liquid chromatography tandem mass spectrum detection phosethyl-Al | |
| CN103235066B (en) | Hanging drop liquid phase micro-extraction method for extracting aroma component in tobacco leaf | |
| CN109781914B (en) | QuEChERS method for detecting pesticide residue based on purifying agent state switching | |
| CN105738514A (en) | Method for detecting pesticide residues through stirring rod adsorption and extraction | |
| CN107505421A (en) | The rapid extraction and purification method of ethiprole and its metabolite residue in a kind of birds, beasts and eggs | |
| CN212067818U (en) | Gas-assisted liquid-liquid micro-extraction device for pretreatment of water quality inspection | |
| CN103728399A (en) | Single-walled carbon nanohorn dispersion liquid-based dispersive micro solid phase extraction method | |
| CN107703221A (en) | It is a kind of while determine the method for RABEPRAZOLE SODIUM and its metabolin in Beagle dog plasmas |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |