Standard No.:	SH/T 1817-2017
English Name:	Plastics. Determination of residual acetaldehyde in polyethylene terephthalate(PET)resin for bottles. Headspace gas chromatography
Chinese Name:	塑料 瓶用聚对苯二甲酸乙二醇酯（PET）树脂中残留乙醛含量的测定 顶空气相色谱法
Professional Classification:	SH    Professional Standard - Petrochemical
Source Content Issued by:	Ministry of Industry and Information Technology
Issued on:	2017-07-07
Implemented on:	2018-1-1
Status:	valid
Target Language:	English
File Format:	PDF
Word Count:	4500 words
Translation Price(USD):	110.0
Delivery:	via email in 1 business day

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. This standard is drafted in accordance with the rules given in the GB/T 1.1-2009. This standard was proposed by China Petrochemical Corporation. This standard is under the jurisdiction of Subcommittee 1 on Petrochemical Plastic Resin Product of National Technical Committee 15 on Plastic of Standardization Administration of China (SAC/TC15/SC1). Plastics — Determination of Residual Acetaldehyde in Polyethylene Terephthalate (PET) Resin for Bottles — Headspace Gas Chromatography 1 Scope This standard specifies the headspace gas chromatography for determination of residual acetaldehyde in polyethylene terephthalate (PET) resin for bottles. This standard is applicable to the determination of residual acetaldehyde in polyethylene terephthalate (PET) resin for bottles. The detection range of residual acetaldehyde in polyethylene terephthalate (PET) resin is 0.1 μg/g to 4 μg/g. 2 Principle The sample is crushed and powders of a specified size are weighed into a sealed container. The sample will release residual acetaldehyde at a certain temperature. After the equilibrium is reached, the gas above the sealed container is injected onto a gas chromatographic column. The acetaldehyde is separated from other components, and detected by hydrogen flame ionization detector. The acetaldehyde released from the sample is quantitatively calculated by the external standard method. 3 Normative References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 601 Chemical Reagent — Preparations of Reference Titration Solutions GB/T 6682 Water for Analytical Laboratory Use — Specifications and Test Methods GB/T 8170 Rules of Rounding of for Numerical Values & Expression and Judgement of Limiting Values 4 Reagents and Materials Unless otherwise specified, only the analytical reagents and Grade 3 water or water with equivalent purity conforming to the requirements of GB/T 6682 are used in analysis. 4.1 Acetaldehyde: chromatographically pure, or acetaldehyde aqueous solution with a concentration of 1 mg/mL and other known concentrations. 4.2 Nitrogen, with purity not less than 99.99%; Prior to use, it shall be purified with dehydration device, silica gel, molecular sieve or activated carbon. 4.3 Hydrogen: with purity not less than 99.8%. Prior to use, it shall be purified with dehydration device, silica gel, molecular sieve or activated carbon. 4.4 Air: it shall be free from corrosive impurities. Prior to use, it shall be dehydrated and degreased. 5 Apparatus 5.1 Gas chromatograph: equipped with hydrogen flame ionization detector and packed column injection inlet. 5.2 Chromatographic working station or integrator. 5.3 Headspace sampler 5.4 Chromatographic column: glass packed column or stainless steel packed column,2.2 m in length, 6.35 mm in inner diameter, using polystyrene porous polymer microsphere stationary phase (such as Porapak-Q), or other columns with the same separation effect can be used. 5.5 Refrigerator. 5.6 Headspace bottle: 20 mL, equipped with aluminum cap and silicone rubber gasket covered with PTFE film. 5.7 Crimper. 5.8 Decapper. 5.9 Sample crusher. 5.10 Liquid nitrogen container. 5.11 Analytical balance: with an accuracy of 0.1 mg. 5.12 Microinjector: 10 μL; 5.13 Glass bottle with fluoropolymer lined diaphragm gasket. 6 Preparation and storage of acetaldehyde standard solution 6.1 Preparation and calibration of acetaldehyde standard solution Prepare the acetaldehyde standard solution according to Annex A, and calibrate the concentration of prepared solution. 6.2 Storage of acetaldehyde standard solution After preparation and calibration of the acetaldehyde standard solution, the solution shall be immediately transferred into the glass bottle with fluoropolymer lined diaphragm gasket (5.13), until the solution is overflowed so as to eliminate the air and guarantee that there is no air in the container; then seal it, stick mark on it and put it into the refrigerator (5.5) for standby. Note: It is recommended to use certified acetaldehyde standard solution or prepare with pure acetaldehyde reagent. The recommended storage life of unopened acetaldehyde standard solution is 3 to 6 months.

Foreword II 1 Scope 2 Principle 3 Normative References 4 Reagents and Materials 5 Apparatus 6 Preparation and storage of acetaldehyde standard solution 7 Test Procedure 8 Calculation of Results 9 Expression of Results 10 Precision Annex A (Normative) Preparation and Ccalibration of 1 mg/mL Acetaldehyde Standard Solution Annex B (Informative) Recommended Operating Conditions for Gas Chromatograph and Headspace Sampler Annex C (Informative) Chromatogram of typical sample of acetaldehyde