CN201508353U - Gas chromatograph capable of checking various pesticide residues in vegetable and fruit synchronously - Google Patents

Abstract

The utility model discloses a gas chromatograph capable of checking various pesticide residues in vegetable and fruit synchronously, wherein more than one group of checking channels comprise a main chromatographic column connected with a sample inlet, the main chromatographic column is connected with two auxiliary chromatographic columns with opposite polarities through a distributor, and the two auxiliary chromatographic columns are respectively connected with an ECD checker and an NPD checker. When two groups of checking channels are arranged, the main chromatographic columns in each checking channel have opposite polarities. Compared with the prior art, after samples of the utility model are grouped and enter the sample inlet, the main chromatographic columns are separated and arrive at the electronic catching detector (ECD) and nitrogen phosphorous detector (NPD) after being distributed by the distributor, the purpose of checking various pesticide residues simultaneously is realized, more importantly, the checked object materials generate two retaining times and two response values on the ECD checker and the NPD checker after being separated by the auxiliary chromatographic columns with opposite polarities, thereby greatly improving the qualitative ability of the checked object materials and greatly improving the accuracy, the whole process only needs 30 minutes, and the gas chromatograph has the advantages of rapid checking range, rapidness, accuracy and low cost.

Description

Detect the gas chromatograph of the many residues of pesticides of multiclass in the vegetable and fruit simultaneously

Technical field

The utility model relates to the detector of the many residues of pesticides of a kind of multiclass, especially refers to a kind of gas chromatograph that can detect the many residues of pesticides of multiclass in the vegetable and fruit simultaneously.

Background technology

At present, agricultural residual detection method master has enzyme inhibition rate method and chemical analysis method, and the former detection speed is fast, and expense is cheap.But fatal technological deficiency is arranged: (1) can not carry out qualitative to remains of pesticide; (2) can not carry out quantitatively remains of pesticide.(3) sensing range is limited, only can detect organophosphorus and carbamate two class agricultural chemicals.The latter mainly contains vapor-phase chromatography, liquid phase chromatography, methods such as gas chromatography mass spectrometry method, be qualitative-and-quantitative method, but the ubiquity investment is big, sense cycle is long, complex steps, shortcoming with high costs, Ministry of Agriculture's NY/T 1380-2007 method and NY/T 761-2008 method as widespread use, the former adopts 51 kinds of residues of pesticides of GC-MS (gas chromatograph-mass spectrometer (GCMS)) detection (to comprise organophosphorus, carbamate, four big class agricultural chemicals such as organochlorine and pyrethroid), initial investment is big 1,200,000 yuan, detect cost height (60 yuan /), sense cycle long (about 2 hours of single sample sense cycle); The latter adopts gas chromatograph and liquid chromatograph to detect kind surplus the four big class agricultural chemicals 90 such as organophosphorus, carbamate, organochlorine and pyrethroid jointly, initial investment needs 1,500,000 yuan, detect cost higher (70 yuan /), sense cycle longer (about 4 hours of single sample sense cycle).In existing detecting instrument, lack the checkout equipment of qualitative, quantitative quick, with low cost.

The utility model content

At the deficiencies in the prior art part, the utility model provides a kind of gas chromatograph simple in structure, and it has improved the qualitative ability of testing goal thing greatly, and accuracy greatly improves, and has the advantage that sensing range is wide, quick, accurate, cost is low.

For achieving the above object, technical solutions of the utility model are:

Detect the gas chromatograph of the many residues of pesticides of multiclass in the vegetable and fruit simultaneously, be provided with one group of above sense channel in this gas chromatograph, this sense channel comprises a main chromatographic column that is connected with injection port, this main chromatographic column is joined through a divider and two opposite polarity auxilliary chromatographic columns, and this two auxilliary chromatographic column connects electron capture detector (ECD) and nitrogen phosphorous detector (NPD) respectively.

When sense channel was two groups, the mass-tone spectrum column polarity in every group of sense channel was opposite.

The usefulness of technique scheme is:

Sense channel of the present utility model can be made as more than one group, when on instrument detecting, adopting the single channel gas chromatograph, sample component is behind the injection port sample introduction, main chromatographic column is separated, after distributing, divider arrives electron capture detector (ECD) and nitrogen phosphorous detector (NPD), realize single injected sampling, detect the purpose of the many residues of pesticides of multiclass (54 kinds of agricultural chemicals or more) simultaneously, the more important thing is, the testing goal thing is through the separation of opposite polarity auxilliary chromatographic column, on electron capture detector and nitrogen phosphorous detector, produce 2 retention times and 2 responses, improved the qualitative ability of testing goal thing greatly, accuracy greatly improves, and overall process only 30 minutes, and it is wide to have sensing range, fast, accurately, the advantage that cost is low.As on instrument detecting, adopting the binary channels gas chromatograph to detect, then not only can detect 2 samples simultaneously, detection efficiency is significantly improved, more because the mass-tone of two sense channels spectrum column polarity is opposite, two passages can be verified mutually, further improve the qualitative ability of testing goal thing, reach higher qualitative accuracy.

Description of drawings

Fig. 1 is the structural representation of the utility model single channel gas chromatograph;

Fig. 2 is the structural representation of the utility model binary channels gas chromatograph.

Embodiment

Now with example the utility model is described in conjunction with the accompanying drawings.

The single channel gas chromatograph that adopts on instrument detecting as shown in Figure 1 detects, this gas chromatograph is installed an injection port 1, a main chromatographic column 2 (30 meters long, 0.53 micron internal diameter), main chromatographic column 2 is distributed through divider 3, connect electron capture detector (ECD) 6 and nitrogen phosphorous detector (NPD) 7 respectively by two opposite polarity auxilliary chromatographic columns 4,5 (10 meters long, 0.32 micron internal diameter), make electron capture detector (ECD) 6 and nitrogen phosphorous detector (NPD) 7 parallel connections, become a sense channel.

The utility model can also adopt the binary channels gas chromatograph to detect on instrument detecting, its each sense channel connects with identical with above-mentioned single channel gas chromatograph, as shown in Figure 2, article one, sense channel is in regular turn by injection port 1, main chromatographic column 2, divider 3, two opposite polarity auxilliary chromatographic columns 4,5 and electron capture detector 6 and nitrogen phosphorous detector 7 form, another sense channel in regular turn by injection port 1 ', main chromatographic column 2 ', divider 3 ', two opposite polarity auxilliary chromatographic columns 4 ', 5 ' and electron capture detector 6 ' and nitrogen phosphorous detector 7 ' composition, but two main chromatographic columns 2 and 2 ' polarity opposite.

The utility model adopts ethyl acetate extraction in specimen preparation, unique cleanser prescription disperses to purify, and preparation process is simply efficient, and each specimen preparation only needs 10 minutes, and sample average only needs 3 minutes in batches.Its concrete testing process is as follows:

1, instrument of Cai Yonging and reagent

The method agents useful for same does not allly indicate specification person, be analyze pure.

1.1 ethyl acetate (chromatographically pure).

1.2 anhydrous magnesium sulfate, 550 ℃ were toasted 4 hours

1.3 sodium chloride, 140 ℃ of baking 4h.

(1.4PSA N-propyl group ethylenediamine bonded silica gel)

(1.5C18 octadecyl silane)

1.6 graphitic carbon

1.7 Florey silicon soil, 550 ℃ were toasted 4 hours

1.8 standard sample of pesticide, as shown in Figure 3.

1.9 assay laboratory's common instrument equipment.

1.10 vortex mixer.

1.11 refiner.

1.12 refrigerated centrifuge (SIGMA-3K15).

1.13 single channel gas chromatograph concrete structure as shown in Figure 1, or binary channels gas chromatograph concrete structure as shown in Figure 2, the simple three links that divider 3,3 ' employing quartz or stainless steel are made also can be the separate system of being with the gas flow electronic control function.

54 kinds of standard sample of pesticide (100ng/ μ l) complete list

Preface	Chinese name	English name	Standard value	Uncertainty	Solvent	Group
							1	Meta-tolyl-N-methylcarbamate (MTMC)	metolcarb	100ng/μl	±0.21ng/μl	Acetone	1
2	α-666	α-666	100ng/μl	±0.13ng/μl	Sherwood oil	1
							3	Lindane	γ-666	100ng/μl	±0.13ng/μl	Sherwood oil	1
4	Bravo	Chlorothalonil	100ng/μl	±0.21ng/μl	Sherwood oil	1
							5	δ-666	δ-666	100ng/μl	±0.13ng/μl	Sherwood oil	1
6	Isocarbophos	isocarbophos	100ng/μl	±0.21ng/μl	Acetone	1
							7	O，P’-DDT	O，P’-DDT	100ng/μl	±0.13ng/μl	Sherwood oil	1
8	Biphenthrin	bifenthrin	100ng/μl	±0.16ng/μl	Sherwood oil	1
							9	Lambda-cyhalothrin	lambda-cyhalothrin	100ng/μl	±0.15ng/μl	Sherwood oil	1
10	DDVP	dichiorvos	100ng/μl	±0.13ng/μl	Acetone	2
							11	Mobucin	lsoprocarb	100ng/μl	±0.21ng/μl	Acetone	2
12	Flolimat	omethoate	100ng/μl	±0.23ng/μl	Acetone	2
							13	β-666	β-666	100ng/μl	±0.13ng/μl	Sherwood oil	2
14	The malathion	malathion	100ng/μl	±0.15ng/μl	Acetone	2
							15	Triazolone	traidimefon	100ng/μl	±0.25ng/μl	Sherwood oil	2
16	O，P’-DDD	O，P’-DDD	100ng/μl	±0.13ng/μl	Sherwood oil	2
							17	Iprodione	iprodione	100ng/μl	±0.06ng/μl	Benzene	2
18	Fenvalerate	fenvalerate	100ng/μl	±0.15ng/μl	Sherwood oil	2
							19	Metrifonate	trichlorfon	100ng/μl	±0.25ng/μl	Acetone	3
20	Arprocarb	Arprocarb	100ng/μl	±0.05ng/μl	Acetone	3
							21	Rogor	dimethoate	100ng/μl	±0.21ng/μl	Acetone	3
22	Vinclozolin	vinclozolin	100ng/μl	±0.15ng/μl	Acetone	3
							23	Entex	fenthion	100ng/μl	±0.15ng/μl	Acetone	3
24	O，P’-DDE	O，P’-DDE	100ng/μl	±0.13ng/μl	Sherwood oil	3

Preface	Chinese name	English name	Standard value	Uncertainty	Solvent	Group
							25	P，P’-DDD	P，P’-DDD	100ng/μl	±0.13ng/μl	Sherwood oil	3
26	Fenpropathrin	fenpropathrin	100ng/μl	±0.15ng/μl	Sherwood oil	3
							27	Decis	deltamethrin	100ng/μl	±0.15ng/μl	Sherwood oil	3
28	Profenofos	Profenofos	100ng/μl	±0.15ng/μl	Acetone	4
							29	Pentachloronitrobenzene	pentachloronitrobenzene	100ng/μl	±0.10ng/μl	Benzene	4
30	Azodrin	monocrotophos	100ng/μl	±0.23ng/μl	Acetone	4
							31	Parathion-methyl	parathion-methyl	100ng/μl	±0.15ng/μl	Acetone	4
32	Fenifrothion	fenitrothion	100ng/μl	±0.17ng/μl	Methyl alcohol									4
							33	P，P’-DDE	P，P’-DDE	100ng/μl	±0.13ng/μl	Sherwood oil	4
34	Hostathion	Triazophos	100ng/μl	±0.12ng/μl	Acetone									4
							35	Phosmet	phosmet	100ng/μl	±0.12ng/μl	Acetone			4
36	Flucythrinate	flucythrinate	100ng/μl	±0.17ng/μl	Sherwood oil	4
							37	Acephatemet	methamidaphos	100ng/μl	±0.23ng/μl	Acetone	5
38	Thimet	phorate	100ng/μl	±0.15ng/μl	Acetone	5
							39	Aphox	Pirimicarb	100ng/μl	±0.23ng/μl	Acetone	5
40	Chlopyrifos	chlorpyrifos	100ng/μl	±0.08ng/μl	Acetone	5
							41	Parathion	parathion	100ng/μl	±0.15ng/μl	Acetone	5
42	Procymidone	procymidone	100ng/μl	±0.23ng/μl	Acetone	5
							43	P，P’-DDT	P，P’-DDT	100ng/μl	±0.13ng/μl	Sherwood oil	5
44	Phosalone	phosalone	100ng/μl	±0.21ng/μl	Acetone	5
							45	Cypermethrin	cypermethrin	100ng/μl	±0.15ng/μl	Sherwood oil	5
46	Orthene	acephate	100ng/μl	±0.18ng/μl	Acetone	6
							47	Bassa	fenobucarb	100ng/μl	±0.23ng/μl	Acetone	6
48	Carbofuran	Carbofuran	100ng/μl	±0.25ng/μl	Acetone	6

Preface	Chinese name	English name	Standard value	Uncertainty	Solvent	Group
							49	Phosphamidon	phosphamidon	100ng/μl	±0.12ng/μl	Acetone	6
50	Carbaryl	Carbaryl	100ng/μl	±0.25ng/μl	Acetone	6
							51	Phoxim	phoxim	100ng/μl	±0.25ng/μl	Acetone	6
52	Permethrin	permethrin	100ng/μl	±0.15ng/μl	Sherwood oil	6
							53	Cyfloxylate	Cyfluthrin	100ng/μl	±0.17ng/μl	Sherwood oil	6
54	Taufluvalinate	Fluvalinate	100ng/μl	±0.16ng/μl	Sherwood oil	6

As above show, single pesticide standard solution: standard sample of pesticide is bought from east, Tianjin green science and technology company

[Ministry of Agriculture environmental monitoring center (Tianjin)], concentration is 100ng/ml.

Agricultural chemicals mixed standard solution: according to response and the agricultural chemicals grouping of each agricultural chemicals on instrument, the single on the same group pesticide standard solution of drawing certain volume one by one injects same volumetric flask respectively, is diluted to scale with ethyl acetate and is mixed with agricultural chemicals hybrid standard working solution.

2, method step

2.1 sample pre-treatments

Get and be no less than 1000g vegetable and fruit sample, get edible part, wipe the attachment of sample surfaces with clean gauze gently, adopt the diagonal line split plot design, get the diagonal angle part, its chopping, fully mixing is put the pulverizing of people's food processing equipment, makes and treats test sample, puts into the packing containers for future use.

2.2 specimen preparation

2.2.1 extraction

Accurately take by weighing above-mentioned test portion 10g and put in the people 50ml centrifuge tube, add 10.0mL ethyl acetate, cover stopper, concuss 30 seconds adds anhydrous magnesium sulfate 10g and sodium chloride 1g, concuss 30 seconds, and 5000 rev/mins in hydro-extractor is centrifugal 2 minutes.

2.2.2 purify

Get the supernatant 1ml among the 2.2.1, the less vegetable sample extract of pigment adds (PSA 20mg+C1850mg+ anhydrous magnesium sulfate 150mg+ Florey silicon soil 50mg); The more vegetable sample extract of pigment adds (PSA 20mg+C1850mg+ anhydrous magnesium sulfate 150mg+ graphitic carbon 20mg), crosses 0.45 micron filter membrane behind the concuss, and filtrate is collected in machine testing on the sample introduction bottle.

2.3 the single channel gas chromatograph detects

2.3.1 chromatogram reference conditions

A master's chromatographic column 2 or 2 ' model specification are DB-1701 or DB-1,30m * 0.53mm * 0.25 μ m;

B ECD and NPD detecting device adopt parallel way

As shown in the figure, main chromatographic column 2 or 2 ' connect divider 3 or 3 ', the auxilliary chromatographic column 4 or 4 of divider 3 or 3 ' connect ' and 5 or 5 ', auxilliary chromatographic column 4 or 4 ' (model specification DB-110m * 0.32mm * 0.25 μ m) connect ECD detecting device 6 or 6 '; Auxilliary chromatographic column 5 or 5 ' (model specification is DB-1701,10m * 0.32mm * 0.25 μ m) connect NPD detecting device 7 or 7 '.By above connection, ECD and NPD detecting device are realized in parallel, and sample is from injection port 1 or 1 ' sample introduction, through main chromatographic column 2 or 2 ' separation, the testing goal thing is through divider 3 or 3 ' distribution, arrives to connect ECD detecting device 6 or 6 ' and NPD detecting device 7 or 7 ' and produce response.

The c temperature

Injection port 1 or 1 ' temperature are made as 250 ℃; 320 ℃ of ECD detecting devices 6 or 6 ' be, NPD detecting device 7 or 7 ' temperature are 300 ℃; Main chromatographic column 2 or 2 ' (column oven) temperature then keeps 2min with 150 ℃ earlier, then be warming up to 180 ℃ with 15 ℃/min, then be warming up to 205 ℃ with 5 ℃/min, then be warming up to 220 ℃ with 3 ℃/min, then be warming up to 240 ℃ with 8 ℃/min, then be warming up to 260 ℃, then be warming up to 270 ℃, and keep 6.5min with 10 ℃/min with 15 ℃/min.

D gas and flow

Carrier gas: nitrogen, purity 〉=99.999%, flow velocity are 6mL/min.

NPD detecting device 7 or 7 ' in: combustion gas: hydrogen, purity 〉=99.999%, flow velocity are 3mL/min.

Combustion-supporting gas: air, flow velocity are 60mL/min.

Make-up gas : nitrogen, 5mL/min.

ECD detecting device 6 or 6 ' in: post stream+make-up gas : nitrogen, 60mL/min.

2.3.2 input mode: split sampling 2 μ l not

2.4 the binary channel gas chromatograph detects

2.4.1 chromatogram reference conditions

A mass-tone spectrum post model specification:

Main chromatographic column 2 as shown in Figure 2 ' (model specification DB-1701,30m * 0.53mm * 0.25 μ m);

Main chromatographic column 2 as shown in Figure 2 (model specification is DB-1,30m * 0.53mm * 0.25 μ m);

B ECD and NPD detecting device parallel way

Main chromatographic column 2 or 2 ' after connect divider 3 or 3 ', divider 3 ' after connect auxilliary chromatographic column 4 ' and 5 ', connect auxilliary chromatographic column 4 and 5 behind the divider 3.Auxilliary chromatographic column 5 or 5 ' (model specification is DB-1701,10m * 0.32mm * 0.25 μ m) connect NPD detecting device 7 or 7 '; Auxilliary chromatographic column 4 or 4 ' model specification DB-1,10m * 0.32mm * 0.25 μ m) connect ECD detecting device 6 or 6 '.By above connection, be linked to be 2 detection path, ECD and NPD detecting device are realized in parallel, and sample separates through principal post from the injection port sample introduction, and the testing goal thing distributes through divider, arrives ECD and NPD detecting device and produces response.

Parameter such as temperature and gas flow is with 2.3

2.5 qualitative, quantitative

2.5.1 table of corrections:

Advance the standard model sample 2 μ l of above-mentioned grouping by group by the 2.3. chromatographic condition, and data such as retention time that each group is recorded, correction factor add one by one in the same table of corrections to, be formed with the single channel table of corrections of 54 kinds of agricultural chemicals information.

Press 2.4 chromatographic conditions sample introduction 2 μ l by group, and the data such as retention time, correction factor of respectively organizing that passage one records are added in the same table of corrections one by one, be formed with passage one table of corrections of 54 kinds of agricultural chemicals information; The data such as retention time, correction factor of respectively organizing that passage two records are added in the same table of corrections one by one, be formed with passage two table of corrections of 54 kinds of agricultural chemicals information

2.5.2 qualitative:

For the single channel gas chromatograph, carry out qualitatively with 2 retention times of recognizate and 2 detecting device corrected concentrations contrast table of corrections, only there is the agricultural chemicals of one group of retention time and relative detector response then to contrast qualitative with retention time and table of corrections.

For the binary channels gas chromatograph, 2 retention times and 2 detecting device corrected concentrations contrast table of corrections with recognizate carry out qualitative, for the agricultural chemicals that on a passage, has only one group of retention time and relative detector response, then at another passage sample introduction, obtain the retention time and the relative detector response of second channel, contrast table of corrections separately is qualitative respectively, and is qualitative with retention time and table of corrections contrast.

2 retention times of same compound are consistent on 2 retention times of the recognizate of the unknown and table of corrections, and the corrected concentrations of ECD and NPD response when also consistent, can confirm that this unknown recognizate is this compound after the influence of deduction matrix.

2.5.3 quantitatively: the sample peak area that organophosphorus and carbamate pesticide obtain with the NPD detecting device and standard specimen peak area ratio be quantitative (external standard method); The sample peak area that organochlorine and pyrethrin pesticide obtain with the ECD detecting device and standard specimen peak area ratio be quantitative (external standard method).

Tested persticide residue is in massfraction ω in the sample, and numerical value is with every kilogram of milligram (mg/kg) expression, and by formula calculate (1).

ω＝[(A×V)/(As×m)]×Ψ……………………………………….(1)

In the formula:

The content of agricultural chemicals in Ψ-standard solution, unit are mg/litre (mg/L);

The peak area of tested agricultural chemicals in the A-sample;

The peak area of tested agricultural chemicals in the As-pesticide standard solution;

V-extracts the solvent cumulative volume;

The quality of m-sample.

2..5.4 precision

Add 54 kinds of agricultural chemicals mixed standard solutions to carry out method in the vegetable sample (spinach and eggplant) precision test at 0.05mg/L, 0.10mg/L and three levels of 0.50mg/L, the coefficient of variation is less than 20%.

2.5.5 the recovery

Add 54 kinds of agricultural chemicals mixed standard solutions to carry out method in the vegetable sample (spinach and eggplant) recovery test at 0.05mg/L, 0.10mg/L and three levels of 0.50mg/L, the interpolation recovery of method is between 70%～120%.

2.5.6 detection limit

The detection limit of method is at 0.0010mg/kg～0.2500mg/kg.

Claims (2)

1. detect the gas chromatograph of the many residues of pesticides of multiclass in the vegetable and fruit simultaneously, it is characterized in that: be provided with one group of above sense channel in this gas chromatograph, this sense channel comprises a main chromatographic column that is connected with injection port, this main chromatographic column is joined through a divider and two opposite polarity auxilliary chromatographic columns, and this two auxilliary chromatographic column connects electron capture detector ECD and nitrogen phosphorous detector NPD respectively.

2. the gas chromatograph that detects the many residues of pesticides of multiclass in the vegetable and fruit simultaneously as claimed in claim 1 is characterized in that: when sense channel was two groups, the mass-tone spectrum column polarity in every group of sense channel was opposite.

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