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SN/T 1071.1-2019 PDF English

SN/T 1071.1: Evolution and historical versions

Std ID	Contents [version]	USD	STEP2	[PDF] delivered in	Standard Title (Description)	Status
SN/T 1071.1-2019	English	190	Add to Cart	0--9 seconds. Auto-delivery	Determination of cinmethylin residue in cereals for export
SN/T 1071-2014	English	125	Add to Cart	0--9 seconds. Auto-delivery	Method for the determination of anaerobic sulfite-reducing clostridia in food for export	Valid
SN/T 1071-2002	English	319	Add to Cart	3 days [Need to translate]	Anaerobic sulfite reduction in the import and export food Clostridium test methods	Obsolete

Standard similar to SN/T 1071.1-2019

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Basic data

Standard ID	SN/T 1071.1-2019 (SN/T1071.1-2019)
Description (Translated English)	Determination of cinmethylin residue in cereals for export
Sector / Industry	Commodity Inspection Standard (Recommended)
Classification of Chinese Standard	C53
Word Count Estimation	9,926
Date of Issue	2019-12-27
Date of Implementation	2020-07-01
Older Standard (superseded by this standard)	SN/T 1017.1-2001
Regulation (derived from)	Announcement No. 222 (2019) of the General Administration of Customs
Issuing agency(ies)	General Administration of Customs

SN/T 1071.1-2019: Determination of cinmethylin residue in cereals for export

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Determination of cinmethylin residue in cereals for export

Foreword

This standard was drafted in accordance with the GB/T 1.1—2009. This standard is the revision of SN/T 1017.1— 2001《Method for the determination of cinmethylin residues in cereals for export》. The differences between this standard and SN/T 1017.1— 2001 are as follows : — Changed the name of the standard ； — Extended the scope to the matrices of unpolished rice, rice, barley, wheat, corn and mung bean ； — Added LC-MS/MS method. Please pay attention that some contents in this standard may refer to patents. The institution doesn’t take on the responsibility to identify these patents. This standard is proposed by and is under the charge of General Administration of Customs of the People’s Republic of China. This standard was drafted by Hangzhou Customs District of the People’s Republic of China. The main drafters of this standard are Huang Chaoqun, Xie Wen, Li Yi, Lou Chengjie, Tong Yunkai, Jiang Qinting, Chen Li. This standard replaces the standard previous published as : — SN/T 1017.1— 2001. Method for the determination of cinmethylin residue in cereals for export

1 Scope

This standard specifies the determination of cinmethylin in cereals for export by gas chromatography-mass spectrometry and gas chromatography-tandem mass spectrometry. This standard is applicable to the determination of cinmethylin in unpolished rice, rice, barley, wheat, corn and mung bean for export.

2 Normative references

The following documents is necessary for this standard. For dated references, only dated editions shall apply to this standard. For undated references, the latest edition of the normative document referred to applies. GB/T 6682 Water for analytical laboratory use— specification and test methods Method Ⅰ GC-MS Method

3 Principle

Cinmethylin in the test samples is extracted with water-acetone. The extract is partitioned with hexane, cleaned up by florisil solid phase and detected by gas chromatography-mass spectrometry using external standard method.

4 Reagents and materials

Unless otherwise specified, all the reagents used should be chromatographic grade, “water” is the first grade water prescribed by GB/T 6682. 4.1 Acetone. 4.2 Hexane. 4.3 Diethyl ether. 4.4 Sodium chloride : analytical grade. 4.5 Anhydrous sodium sulfate : analytical grade, Ignite at 650 ℃ for 4h. 4.6 Hexane-diethyl ether (9+1, V/V): Volume 900 mL hexane, then add 100 mL diethyl ether, mix them. 4.7 Sodium chloride solution (50 g/L): dissolve 50 g of sodium chloride in 1 000 mL of water. 4.8 Standard : Cinmethylin, C18H26O2, CAS NO.87818-31-3, concentration of 10 μg/mL, stored under 20 ℃ in the dark. 4.9 Standard work solution : According to the requirement, diluted the standard(4.8) with hexane. Stored under 0 ℃~4 ℃. 4.10 Florisil column : grass column of 270 mm×10 mm(i.d), absorbent cotton and 10 mm of anhydrous sodium sulfate at the bottom, filling with 1 g of florisil (Ignite at 650℃ for 4h), the upper layer was covered with 10 mm of anhydrous sodium sulfate. 4.11 Anhydrous sodium sulfate column : 75 mm×35 mm(i.d), filled with 30 mm of anhydrous sodium sulfate.

5 Apparatus and equipment

5.1 Gas chromatography-mass spectrometer, equipped with EI source. 5.2 Electronic balance : accurate to 0.000 1 g and 0.01 g. 5.3 Vortex mixer. 5.4 Oscillator. 5.5 Rotary vacuum evaporator.

6 Preparation and storage of test sample

6.1 Preparation of test sample Take approximately 500 g of representative unpolished rice, rice, barley, wheat, corn and mung bean, smashed thoroughly by a chopper, mixed thoroughly and put into clean containers, which is sealed and labeled. 6.2 Storage of test sample Test samples should be stored at a temperature ranged from 0 ℃~4 ℃. In course of sampling and sample preparation, attention must be taken to avoid contamination or any factors which may cause the change of residue content.

7 Procedure

7.1 Extraction Weigh 10 g (accurate to 0.01 g) of the test samole into a 100 mL concial flask. Add 15 mL of water, soak for 2h, add 15 mL of acetone and shake for 30 min, then filter. Extract the residues once more with 15 mL of acetone. Combine the filtrates in a 250 mL separatory funnel. Add 5 mL of sodium chloride solution, and then extract with 20 mL and 20 mL of hexane respectively. Combine the hexane layers and pass through the column of anhydrous sodium sulfate, then condensed to dry, waiting for cleaning-up. 7.2 Cleaning-up Add 10 mL of hexane to dissolve the residue. 1.0 mL of the solution was transfered to a florisil column (4.10). After sample loading, the column was washed with 10 mL of hexane, and finally cinmethylin was eluted by 10 mL of hexane-diethyl ether (4.6). The eluate was condensed to dry. Dissolve the residue with 1.0 mL of hexane, and detect by GC-MS. 7.3 Determination 7.3.1 GC-MS operating condition GC-MS operating condition is as follows : a)Chromatographic Column : HP-5MS, 30 m ×0.25 mm (i.d), film thickness 0.25 μm, or equivalent ； b)Column temperature : 60 ℃(1 min) 30℃/min 180℃ 10℃/min 250 ℃(5 min)； c)Injection port temperature : 250℃； d)Carrier gas : Helium, purity ≥ 99.999%, flow rate 1.0 mL/min ； e)Injection volume : 2.0 μL ； f)Injection mode : splitless ； g)Electron ionization mode : EI ； h)Electron ionization energy : 70 eV ； i)Ion source temperature : 230 ℃； j)Quadrupole temperature : 150 ℃； k)Interface temperature : 280 ℃； l)Scan mode : SIM ； m)Selected monitoring ion (m/z): Quantitation 105, Qualification 123, 169 ； n)Solvent delay : 7 min. 7.3.2 Quantitative determination Analyze standard working solutions and samples with external standard menthod using conditions established in sec.7.3.1. If the concentration of cinmethylin exceeds the linear range of the calibration curve, the final solution should be diluted with hexane and reanalyzed. Under the above chromatographic conditions, the retention time of chromatographic peak of cinmethylin is about 9.5 min. For the GC-MS SIM chromatogram refer to fig.A.1 in Appendix A. 7.3.3 Qualitative determination The accordance between the retention time of the test sample solution and the time of the standard, the consistency between the abundance ration of the selected ions from the sample and the ratio of ions from standard, and the similarity subject to the allowance (see table 1), can deliver the positive judgment of analyte detection. 7.4 Blank test The operation of the blank test is the same as that described in the method of determination, but with omission of sample addition.