標準編號:	GB 31604.14-2016
中文名稱:	食品安全國家標準 食品接觸材料及制品 1-辛烯和四氫呋喃遷移量的測定
英文名稱:	National Food Safety Standard - Food Contact Materials and Articles -Determination of Migration of 1-octene and Tetrahydrofuran
行業分類:	GB    國家標準
發布機構:	國家衛生和計劃生育委員會
發布日期:	2016-10-19
實施日期:	2017-4-19
標準狀態:	valid
替代舊標準:	GB/T 23296.4-2009 食品接觸材料 高分子材料 食品模擬物中1-辛烯和四氫呋喃的測定 氣相色譜法
翻譯語言:	英文
文件格式:	PDF
中文字符數:	10000 字
翻譯價格(元):	240.0
交付時間:	付款后 1 個工作日

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 replaces GB/T 23296.4-2009 Food Contact Materials - Polymer - Determination of 1-octene and Tetrahydrofuran in Food Simulants - Gas Chromatography. The following changes have been made with respect to GB/T 23296.4-2009 (the previous edition): ——This standard is renamed as "National Food Safety Standard - Food Contact Materials and Articles - Determination of Migration of 1-octene and Tetrahydrofuran"; ——Gas chromatography-mass spectrometry is added; ——Preparation of food simulant test solution is modified; ——The expression of analysis results is modified; ——The detection limit and the quantitation limit are modified. National Food Safety Standard Food Contact Materials and Articles Determination of Migration of 1-octene and Tetrahydrofuran 1 Scope This standard specifies the determination method for migration of 1-octene and tetrahydrofuran in food contact materials and articles. This standard is applicable to determination of migration of 1-octene and tetrahydrofuran in food contact materials and articles. Method I Gas Chromatography 2 Principle Samples of 1-octene and tetrahydrofuran in food simulants, after subjected to headspace injection, separate from internal standard and other components in the chromatographic column; detect with hydrogen flame ionization detector and carry out quantitative determination by internal standard method. 3 Reagents and Materials Unless otherwise specified, analytically-pure reagents and Class-I water (defined in GB/T 6682) are adopted for the purpose of this method. 3.1 Reagents 3.1.1 N,N-dimethyl acetamide (DMAC, C4H9NO): purity > 99.0%. 3.1.2 Water-based, acidic, alcoholic and oil-based food simulants: the reagents used shall be in accordance with the requirements of GB 31604.1. 3.2 Preparation of reagents 3.2.1 Water-based, acidic, alcoholic and oil-based food simulants: prepare according to GB 5009.156. 3.3 Standard products 3.3.1 1-octene (C8H16; CAS No.: 111-66-0): with purity ≥99.5%, or reference material approved and awarded with reference material certificate by the State. 3.3.2 Isooctane (C8H18; CAS No.: 540-84-1): with purity ≥99.5%, or reference material approved and awarded with reference material certificate by the State. 3.3.3 Tetrahydrofuran (THF, C4H8O; CAS No.: 109-99-9): with purity ≥98.0%, or reference material approved and awarded with reference material certificate by the State. 3.3.4 Tetrahydropyrane (THP, C5H10O; CAS No.: 142-68-7): with purity ≥99.9%, or reference material approved and awarded with reference material certificate by the State. 3.4 Preparation of standard solutions 3.4.1 1-octene standard stock solution (2mg/mL): take 45mL of DMAC and pour it into 50mL volumetric flask, and weigh the volumetric flask with stopper (to the nearest of 0.0001g); add 100 mgof 1-octene (about 150μL), weigh it again (to the nearest of 0.0001g); scale the volume with DMAC, and accurately calculate the concentration of 1-octene; preserve it from light at 4℃, and the validity period is 3 months. 3.4.2 1-octene standard intermediate solution (200μg/mL): accurately take 1.0mL of 1-octene standard stock solution and pour it into a 10mL volumetric flask, and scale the volume with DMAC; preserve it in the same condition as that in 3.4.1. 3.4.3 1-octene standard working solution with medium of water-based, acidic or alcoholic food simulant: respectively pipette 1.0 mL of water-based, acidic and alcoholic food simulants with pipet and pour them into six headspace bottles, and seal them with isolation pads and aluminium caps immediately; add 200 μL of isooctane internal intermediate solutions with microinjector by penetrating the isolation pad, and mix uniformly; add 1-octene standard intermediate solutions and DMAC into the bottles with microinjector by penetrating the isolation pad according to those specified in Table A.1 in Annex A, and mix uniformly. 3.4.4 1-octene standard working solution with medium of olive oil: respectively weigh 1g (to the nearest of 0.01g) of olive oil and put them into six headspace bottles, immediately seal them with isolation pads and aluminium caps, add 200 μL of isooctane internal standard intermediate solutions in sequence with microinjector by penetrating the isolation pad, and mix uniformly; add into the bottles 1-octene standard intermediate solutions and DMAC with the same volume as that of solution in corresponding bottle according to those listed in Table A.1 in Annex A, and mix uniformly. 3.4.5 Isooctane internal standard stock solution (2mg/mL): measure 45mL of DMAC and pour it into 50mL volumetric flask, and weigh the volumetric flask with stopper (to the nearest of 0.001g); add 100mg of isooctane (about 150μL), weigh it again (to the nearest of 0.0001g), and scale the volume with DMAC; accurately calculate the concentration of isooctane; preserve it in the same condition as that in 3.4.1. 3.4.6 Isooctane internal standard intermediate solution (120μg/mL): take 3.0mL of isooctane internal standard stock solution and pour it into a 50mL volumetric flask, and scale the volume with DMAC; preserve it in the same condition as that in 3.4.1. 3.4.7 Water-based, acidic or alcoholic THF standard stock solution (2.2 mg/mL): measure 99 mL of water and pour it into a 100mL volumetric flask and weigh the volumetric flask with stopper (to the nearest of 0.0001g); add 220mg of THF (about 250μL) and weigh it again (to the nearest of 0.0001g), scale the volume with water, and accurately calculate the concentration of THF; preserve it from light at 4℃ and the validity period is 1 week. 3.4.8 Water-based, acidic or alcoholic THF standard intermediate solution (22 μg/mL): measure 90 mL of water and pour it into a 100mL volumetric flask, add into 1.0 mL of water-based THF standard stock solution, scale the volume with water and preserve it in the same condition as that in 3.4.7. 3.4.9 THF standard working solution with medium of water-based, acidic or alcoholic food simulant: respectively measure 45 mL of water-based, acidic and alcoholic food simulants and pour them into six 50mL volumetric flask, add water-based, acidic or alcoholic THF standard intermediate solution with certain volume correspondingly according to those specified in Table A.2, and scale the volume with corresponding food simulants. Accurately take 10.0mL of the above-mentioned solutions respectively and pour them into six headspace bottles, seal them with isolation pads and aluminium caps immediately, pipette 100μL of water-based, acidic or alcoholic THP internal standard intermediate solution with microinjector and add it into corresponding headspace bottle by penetrating the isolation pad, and mix uniformly. 3.4.10 Water-based, acidic or alcoholic THP internal standard stock solution (1 mg/mL): measure 99 mL of water and pour it into a 100mL volumetric flask, and weigh the volumetric flask with stopper (to the nearest of 0.0001g); add 100mg of THP (about 150 μL) and weigh it again (to the nearest of 0.0001g), scale the volume with water, accurately calculate the concentration of THP and preserve it in the same condition as that in 3.4.7. 3.4.11 Water-based, acidic or alcoholic THP internal standard intermediate solution (70 μg/mL): measure 90 mL of water and pour it into a 100mL volumetric flask, add into 7.0 mL of water-based THP internal standard stock solution, scale the volume with water and preserve it in the same condition as that in 3.4.7. 3.4.12 Oily THF standard stock solution (1.0 mg/mL): measure 45 mL of DMAC and pour it into a 50mL volumetric flask and weigh the volumetric flask with stopper (to the nearest of 0.0001 g); add 50 mg of THF (about 60μL) and weigh it again (to the nearest of 0.0001g), scale the volume with DMAC, and accurately calculate the concentration of THF; preserve it in the same condition as that in 3.4.7. 3.4.13 Oily THF standard intermediate solution (50 μg/mL): take 1.0 mL of oily THF standard stock solution and pour it into a 20mL volumetric flask, and scale the volume with DMAC; preserve it in the same condition as that in 3.4.7. 3.4.14 THF standard working solution with medium of olive oil: respectively weigh 10g (to the nearest of 0.01g) of olive oils and put them into six headspace bottles, seal the bottles with isolation pads and aluminium caps immediately, pipette 100μL of oily THP internal standard intermediate solutions with microinjector and add them into headspace bottles respectively, add oily THF standard intermediate solutions and DMAC with certain volume into each headspace bottle according to those specified in Table A.3 to prepare standard working solutions with the concentration similar to those listed in Table A.3. 3.4.15 Oily THP internal standard stock solution (1 mg/mL): take 45 mL of DMAC and pour it into a 50mL volumetric flask and weigh the volumetric flask with stopper (to the nearest of 0.0001 g); add 50 mg of THP (about 60μL) and weigh it again (to the nearest of 0.0001g), scale the volume with DMAC, and accurately calculate the concentration of THP; preserve it in the same condition as that in 3.4.7. 3.4.16 Oily THP internal standard intermediate solution (75 μg/mL): take 1.5 mL of oily THP internal standard stock solution and pour it into a 20mL volumetric flask, and scale the volume with DMAC; preserve it in the same conditions as that in 3.4.7. 4 Instruments and Apparatus 4.1 Gas chromatograph: equipped with automatic headspace sampler and hydrogen flame ionization detector (FID). 4.2 Headspace bottle: 20mL; equipped with aluminium cap and butyl rubber or silicone resin rubber isolation pad whose side contacting sample shall be coated with polytetrafluoroethylene. Note: THF may be used for manufacturing the butyl rubber isolation pad with its inside coated with polytetrafluoroethylene, which may seriously interfere with the THF analysis; thus, before test, the isolation pad shall be subjected to purification treatment, i.e. boil it for at least 15 min with distilled water and then dry it in the air; isolation pads which are purified and unused shall be purified again when used in the next time. 4.3 Volumetric flask: 10mL, 25mL, 50mL and 100mL. 4.4 Microinjector: 25μL, 50μL, 100μL, 250μL and 500μL. 4.5 Pipet: 1mL, 2mL, 3mL, 5mL and 10mL. 4.6 Analytical balance: with sensibility of 0.0001g and 0.01g. 5 Analysis Steps 5.1 Preparation of specimen Carry out migration test for the sample according to the requirements of GB 5009.156 and GB 31604.1 so as to obtain food simulant test solution; if the food simulant test solution obtained cannot be used immediately for the next step of test, it shall be preserved from light at in a 0℃~4℃ refrigerator. The food simulant test solution obtained shall be cooled or recovered to room temperature before being used for the next step of test. 5.2 Preparation of test solutions 5.2.1 Preparation of water-based, acidic or alcoholic food simulant test solution used for 1-octene determination Transfer 1.0mL of water-based food simulant from migration test and pour it into a headspace bottle, and seal the bottle with isolation pad and aluminium cap immediately; add 200μL of isooctane internal standard intermediate solution and 200μL of DMAC in sequence with microinjector by penetrating the isolation pad, and mix uniformly. 5.2.2 Preparation of food simulant test solution with medium of olive oil used for 1-octene determination Weigh 1g (to the nearest of 0.01g) of olive oil medium food simulant from migration test and put it into a headspace bottle, and then operate according to the operation steps in 5.2.1 from "and seal the bottle with isolation pad and aluminium cap immediately… …". 5.2.3 Preparation of water-based, acidic or alcoholic food simulant test solution used for tetrahydrofuran determination Pipette 10.0mL of water-based, acidic or alcoholic food simulant from migration test and pour it into a headspace bottle, and seal the bottle with isolation pad and aluminium cap immediately; add 100μL of water-based, acidic or alcoholic THP internal standard intermediate solution correspondingly with microinjector by penetrating the isolation pad, and mix uniformly. 5.2.4 Preparation of food simulant test solution with medium of olive oil used for tetrahydrofuran determination Weigh 10g (to the nearest of 0.01g) of olive oil medium food simulant from migration test and put it into a headspace bottle, and seal the bottle with isolation pad and aluminium cap immediately; add 100 μL of oily THP internal standard intermediate solution (3.4.16) and then 300μL of DMAC rapidly with microinjector by penetrating the isolation pad, and mix uniformly. 5.3 Preparation of blank test solution Treat the food simulants which have not contacted the food contact materials and articles according to the procedures described in 5.2.

Foreword i 1 Scope 2 Principle 3 Reagents and Materials 4 Instruments and Apparatus 5 Analysis Steps 6 Expression of Analysis Result 7 Accuracy 8 Others 9 Principle 10 Reagents and Materials 11 Instruments and Apparatus 12 Analysis Steps 13 Expression of Analysis Result 14 Accuracy 15 Others Annex A Table for Standard Working Solution Preparation Annex B Standard Product Spectrogram in Gas Chromatography and Gas Chromatography-mass Spectrometry

中華人民共和國國家標準 GB 31604.14—2016 食品安全國家標準 食品接觸材料及制品 1-辛烯和四氫呋喃遷移量的測定 2016—10—19發布 2017—04—19實施 中華人民共和國 國家衛生和計劃生育委員會 發布 前言 本標準代替GB/T 23296.4—2009《食品接觸材料 高分子材料 食品模擬物中1-辛烯和四氫呋喃的測定 氣相色譜法》。 本標準與GB/T 23296.4—2009相比，主要變化如下： ——標準名稱修改為“食品安全國家標準 食品接觸材料及制品 1-辛烯和四氫呋喃遷移量的測定”； ——增加了氣相色譜-質譜法； ——修改了食品模擬物試液的制備； ——修改了分析結果的表述； ——修改了檢出限和定量限。 食品安全國家標準 食品接觸材料及制品 1-辛烯和四氫呋喃遷移量的測定 1 范圍 本標準規定了食品接觸材料及制品中1-辛烯和四氫呋喃遷移量的測定方法。 本標準適用于食品接觸材料及制品中1-辛烯和四氫呋喃遷移量的測定。 第一法 氣相色譜法 2 原理 食品模擬物中1-辛烯、四氫呋喃經頂空進樣后，在色譜柱中與內標物及其他組分分離，用氫火焰離子化檢測器檢測，以內標法定量。 3試劑和材料 除非另有說明，本方法所用試劑均為分析純，水為GB/T 6682規定的一級水。 3.1 試劑 3.1.1 N，N-二甲基乙酰胺(DMAC，C4H9NO)：純度>99.0％。 3.1.2水基、酸性、酒精類、油基食品模擬物：所用試劑依據GB 31604.1的規定。 3.2試劑配制 3.2.1水基、酸性、酒精類、油基食品模擬物：按GB 5009.156操作。 3.3標準品 3.3.1 1-辛烯(C8H16，CAS號：111-66-0)，純度≥99.5％，或經國家認證并授予標準物質證書的標準物質。 3.3.2異辛烷(C8H18，CAS號：540-84-1)，純度≥99.5％，或經國家認證并授予標準物質證書的標準物質。 3.3.3四氫呋喃(THF，C4H8O，CAS號：109-99-9)，純度≥98.0％，或經國家認證并授予標準物質證書的標準物質。 3.3.4四氫吡喃(THP，C5H10O，CAS號：142-68-7)，純度≥99.9％，或經國家認證并授予標準物質證書的標準物質。 3.4標準溶液配制 3.4.1 1-辛烯標準儲備液(2 mg/mL)：量取45 mL DMAC于50 mL容量瓶中，帶塞稱量(精確至0.000 1 g)。再加入1-辛烯100 mg，約150 μL，重新稱量(精確至0.000 1 g)。用DMAC定容。精確計算1-辛烯的濃度。于4℃避光保存，有效期3個月。 3.4.2 1-辛烯標準中間溶液(200 μg/mL)：準確移取1-辛烯標準儲備液1.0 mL于10 mL容量瓶中，用DMAC定容。保存條件同3.4.1。 3.4.3 1-辛烯水基、酸性、酒精類食品模擬物介質標準工作溶液：用移液管分別移取1.0 mL水基、酸性、酒精類食品模擬物于6個頂空瓶中，立即用隔墊和鋁蓋密封。用微量注射器透過隔墊依次加入200 μL異辛烷內標中間溶液，混勻。按附錄A中表A.1用微量注射器透過隔墊向瓶中加入1-辛烯標準中間溶液及DMAC，混勻。 3.4.4 1-辛烯橄欖油介質標準工作溶液：分別稱取1 g(精確至0.01 g)橄欖油于6個頂空瓶中，立即用隔墊和鋁蓋密封。用微量注射器透過隔墊依次加入200 μL異辛烷內標中間溶液，混勻。按照附錄A中表A，1所列，向瓶中加入同樣體積的1-辛烯標準中間溶液及DMAC，混勻。 3.4.5異辛烷內標儲備液(2 mg/mL)：量取45 mL DMAC于50 mL容量瓶中，帶塞稱量(精確至0.001 g)。再加入100 mg異辛烷，約150 μL，重新稱量(精確至0.000 1 g)，用DMAC定容。精確計算異辛烷的濃度。保存條件同3.4.1。 3.4.6 異辛烷內標中間溶液(120 μg/mL)：移取3.0 mL異辛烷內標儲備液于50 mL容量瓶中，用DMAC定容。保存條件同3.4.1。 3.4.7水基、酸性、酒精類THF標準儲備液(2.2 mg/mL)：量取99 mL水于100 mL容量瓶中，帶塞稱量(精確至0.000 1 g)。加入220 mg THF，約250 μL，重新稱重(精確至0.000 1 g)，用水定容。精確計算THF的濃度。于4℃避光保存，有效期1個星期。 3.4.8水基、酸性、酒精類THF標準中問溶液(22 μg/mL)：量取90 mL水于100 mL容量瓶中，再移入1.0 mL水基THF標準儲備液，用水定容。保存條件同3.4.7。 3.4.9 THF水基、酸性、酒精類食品模擬物介質標準工作溶液：分別量取45 mL水基、酸性、酒精類食品模擬物于6個50 mL容量瓶中。按表A.2加入一定體積的水基、酸性、酒精類THF標準中間溶液，用對應的食品模擬物定容。 準確移取上述溶液各10.0 mL分別于6個頂空瓶中，立即用隔墊和鋁蓋密封。用微量注射器移取100μL水基、酸性、酒精類THP內標中間溶液透過隔墊加入各頂空瓶中，混勻。 3.4.10水基、酸性、酒精類THP內標儲備液(1 mg/mL)：量取99 mL水于100 mL容量瓶中，帶塞稱量(精確至0.000 1 g)，加入100 mg THP，約150 μL，重新稱量(精確至0.000 1 g)，用水定容。精確計算THP的濃度。保存條件同3.4.7。 3.4.11 水基、酸性、酒精類THP內標中間溶液(70 μg/mL)：量取90 mL水于100 mL容量瓶中，再移入7.0 mL水基THP內標儲備液，用水定容。保存條件同3.4.7。 3.4.12油性THF標準儲備液(1.0 mg/mL)：量取45 mL DMAC于50 mL容量瓶中，帶塞稱量(精確至0.000 1 g)。再加入50 mg THF，約60μL，重新稱量(精確至0.000 1 g)，用DMAC定容。精確計算THF的濃度。保存條件同3.4.7。 3.4.13油性THF標準中間溶液(50 μg/mL)：移取1.0 mL油性THF標準儲備液于20 mL容量瓶中，用DMAC定容。保存條件同3.4.7。 3.4.14 THF橄欖油介質標準工作溶液：分別稱取10 g(精確至0.01 g)橄欖油于6個頂空瓶中，立即用隔墊和鋁蓋密封。用微量注射器移取100 μL油性THP內標中間溶液透過隔墊分別加入各頂空瓶中。按表A.3所示，向每個頂空瓶中加入一定體積的油性THF標準中間溶液和DMAC，配制與表A.3所列濃度相近的標準工作溶液。 3.4.15油性THP內標儲備液(1 mg/mL)：量取45 mL DMAC于50 mL容量瓶中，帶塞稱量(精確至0.000 1 g)。再加入50 mg THP，約60 μL重新稱量(精確至0.000 1 g)，用DMAC定容。精確計算THP的濃度。保存條件同3.4.7。 3.4.16油性THP內標中間溶液(75 μg/mL)：移取1.5 mL油性THP內標儲備液于20 mL容量瓶中，用DMAC定容。保存條件同3.4.7。 4儀器和設備 4.1氣相色譜儀：配備自動頂空進樣器和氫火焰離子化檢測器(FID)。 4.2頂空瓶：20 mL，配備鋁蓋和丁基橡膠或硅樹脂橡膠隔墊，隔墊接觸樣品一面應涂有聚四氟乙烯。 注：THF可用于制造內涂聚四氟乙烯的丁基橡膠隔墊，這將對THF的分析產生嚴重干擾。因此在試驗前應對隔墊進行凈化處理，用蒸餾水至少煮沸15 min，再晾干。已凈化未使用的隔墊，下次使用時應再次凈化。 4.3容量瓶：10 mL、25 mL、50 mL、100 mL。 4.4微量注射器：25 μL、50 μL、100 μL、250 μL、500 μL。 4.5移液管：1 mL、2 mL、3 mL、5 mL、10 mL。 4.6分析天平：感量0.000 1 g、0.01 g。 5分析步驟 5.1 試樣制備 按照GB 5009.156及GB 31604.1的要求，對樣品進行遷移試驗，得到食品模擬物試液。如果得到的食品模擬物試液不能馬上進行下一步試驗，應將食品模擬物試液于0℃～4℃冰箱中避光保存。 應將所得食品模擬物試液冷卻或恢復至室溫后進行下一步試驗。 5.2試液制備 5.2.1 用于測定1-辛烯的水基、酸性、酒精類食品模擬物試液的制備 從遷移試驗中移取1.0 mL水基食品模擬物于頂空瓶中，立即用隔墊和鋁蓋密封。用微量注射器透過隔墊依次加入200 μL異辛烷內標中間溶液和200 μL DMAC，混勻。 5.2.2用于測定1-辛烯的橄欖油介質食品模擬物試液的制備 從遷移試驗中稱取1 g(精確至0.01 g)橄欖油介質食品模擬物至頂空瓶中，以下按5.2.1“立即用隔墊和鋁蓋密封……”的操作步驟進行處理。 5.2.3用于測定四氫呋喃的水基、酸性、酒精類食品模擬物試液的制備 從遷移試驗中移取10.0 mL水基、酸性、酒精類食品模擬物于頂空瓶中，立即用隔墊和鋁蓋密封。用微量注射器透過隔墊加入100 μL水基、酸性、酒精類THP內標中間溶液，混勻。 5.2.4用于測定四氫呋喃的橄欖油介質食品模擬物試液的制備 從遷移試驗中稱取10 g(精確至0.01 g)橄欖油介質食品模擬物于頂空瓶中，立即用隔墊和鋁蓋密封。用微量注射器透過隔墊加入100 μL油性THP內標中間溶液(3.4.16)，再用微量注射器迅速加入300 μL DMAC，混勻。 5.3空白試液的制備 按照5.2所述步驟處理沒有與食品接觸材料接觸的食品模擬物。 5.4測定 5.4.1 氣相色譜測定參考條件 頂空進樣器條件列出如下： a)樣品平衡時間：60 min； b)頂空瓶溫度：70℃； c)進樣針溫度：70℃； d)平衡罐轉速：500 r/min。 氣相色譜條件列出如下： a)色譜柱：(5％-苯基)-甲基聚硅氧烷石英毛細管柱，柱長30.0 m，內徑0.25 mm，膜厚0.25 μm，或性能類似的分析柱； b)程序升溫：測定1-辛烯時，60℃保持6.5 min，再以30℃/min的速率升溫至240℃，保持3 min；測定四氫呋喃時，50℃保持5 min； c)進樣口溫度：150℃； d)檢測器溫度：300℃； e)載氣：氮氣； f)載氣流速：測定1-辛烯時為1.0 mL/min；測定四氫呋喃時為2.5 mL/min； g)進樣方式：分流進樣，分流比10：1； h)進樣量：280 μL； i)氫氣流速：30 mL/min； j)空氣流速：400 mL/min。 5.4.2繪制標準工作曲線 按照5.4.1所列測定條件，對標準工作溶液依次進樣測定。以標準工作溶液中1-辛烯或四氫呋喃濃度為橫坐標，單位以“mg/L或mg/kg”表示，以1-辛烯/異辛烷或四氫呋喃/四氫吡喃的峰面積比值為縱坐標，繪制標準曲線。標準色譜圖參見圖B.1和圖B.2。 6分析結果的表述 由標準曲線得到試樣溶液中1-辛烯或四氫呋喃的濃度，按GB 5009.156進行遷移量計算，得到食品接觸材料及制品中1-辛烯或四氫呋喃的遷移量。計算結果保留兩位有效數字。 7精密度 在重復性條件下獲得的兩次獨立測定結果的絕對差值不得超過算術平均值的10％。 8其他 本方法的水基、酸性、酒精類模擬物中的1-辛烯和四氫呋喃檢出限分別為2.0 mg/L和0.1 mg/L；橄欖油模擬物中的1-辛烯和四氫呋喃檢出限分別為2.0 mg/kg和0.1 mg/kg。 本方法的水基、酸性、酒精類模擬物中的1-辛烯和四氫呋喃定量限分別為6.0 mg/L和0.3 mg/L；橄欖油模擬物中的1-辛烯和四氫呋喃定量限分別為6.0 mg/kg和0.3 mg/kg。 第二法 氣相色譜-質譜法 9 原理 食品模擬物中1-辛烯、四氫呋喃經頂空進樣后，在色譜柱中與內標物及其他組分分離，用質譜檢測器檢測，以內標法定量。 10試劑和材料 同第3章。 11 儀器和設備 11.1 氣相色譜-質譜聯用儀：配備EI源。 11.2頂空瓶、容量瓶、微量注射器、移液管和分析天平的規格同4.2～4.6。 12分析步驟 12.1 試樣制備 同5.1。 12.2試液制備 同5.2。 12.3空白試液的制備 按照12.2所述步驟處理沒有與食品接觸材料接觸的食品模擬物。 12.4 測定 12.4.1 氣相色譜-質譜測定參考條件 頂空進樣器條件列出如下： a)樣品平衡時間：60 min； b)頂空瓶溫度：70℃； c)進樣針溫度：70℃； d)平衡罐轉速：500 r/min。 氣相色譜-質譜條件列出如下： a)色譜柱：(5％-苯基)-甲基聚硅氧烷石英毛細管柱，柱長30.0 m，內徑0.25 mm，膜厚0.25μm(質譜專用柱)或性能類似的分析柱； b)程序升溫：初始溫度38℃，保持7 min，40℃/min升至240℃，保持3 min； c)進樣口溫度：150℃； d)離子源溫度：230℃； e)載氣：氦氣，0.9 mL/min； f)進樣方式：分流進樣，分流比10：1； g)進樣量：250 μL； h)傳輸線溫度：250℃； i)電離方式：EI； j)溶劑延遲：2.2 min； k)質譜掃描方式：選擇離子模式(SIM)，8 min后關閉燈絲； l)異辛烷定量離子m/z 57，定性離子m/z 58、99；1-辛烯定量離子m/z 70，定性離子m/z 83、112；四氫呋喃定量離子m/z 72，定性離子m/z 71、73；四氫吡喃定量離子m/z 85，定性離子m/z 67、86。 12.4.2繪制標準工作曲線 按照12.4.1所列測定條件，對標準工作溶液依次進樣測定。以標準工作溶液中1-辛烯或四氫呋喃濃度為橫坐標，單位以“mg/L或mg/kg”表示，以1-辛烯/異辛烷或四氫呋喃/四氫吡喃的峰面積比值為縱坐標，繪制標準曲線。氣相色譜-質譜總離子流圖參見附錄B。 12.4.3 確證 取試液(12.2)，參照12.4.1中所述的氣相色譜質譜條件進行內標法確證試驗。參照圖B.3和圖B.4中1-辛烯或四氫呋喃的氣相色譜-質譜總離子流圖，在相同的實驗條件下，如果確證試樣中色譜峰保留時間與標準溶液在±2.5％范圍內，并且在扣除背景后的樣品質譜圖中定性離子的相對豐度與濃度接近的標準溶液譜圖對應的定性離子的相對豐度進行比較，相對豐度偏差不超過表1的規定，則可判斷樣品中存在相應的待測物。 表1 定性確證時相對離子豐度的最大允許偏差 相對離子豐度 >50％ 20％～50％ 10％～20％ ≤10％ 允許的相對偏差 +20％ +25％ +30％ +50％ 13分析結果的表述 同6。 14精密度 在重復性條件下獲得的兩次獨立測定結果的絕對差值不得超過算術平均值的10％。 15其他 本方法的水基、酸性、酒精類模擬物中的1-辛烯和四氫呋喃檢出限分別為2.0 mg/L和0.1 mg/L；橄欖油模擬物中的1-辛烯和四氫呋喃檢出限分別為2.0 mg/kg和0.1 mg/kg。 本方法的水基、酸性、酒精類模擬物中的1-辛烯和四氫呋喃定量限分別為6.0 mg/L和0.3 mg/L；橄欖油模擬物中的1-辛烯和四氫呋喃定量限分別為6.0 mg/kg和0.3 mg/kg。 附 錄 A 標準工作溶液配制表 表A.1 標準工作溶液中1-辛烯和DMAC的體積 標準工作溶液 加入1-辛烯標準中間溶液的量 μL 加入DMAC的量 μL 在標準工作溶液中1-辛烯的近似濃度 mg/L 0 0 200 0 1 10 190 2 2 50 150 10 3 75 125 15 4 100 100 20 5 150 50 30 表A.2水基、酸性、酒精類TIIF標準工作溶液中TIIF的體積 標準工作溶液 加入水基、酸性、酒精類THF標準中間溶液添加量 mL 標準工作溶液中THF濃度 mg/L 0 0 0 1 0.2 0.09 2 0.5 0.22 3 1.5 0.66 4 2.5 1.10 5 3.5 1.54 表A.3油性TIIF標準工作溶液中TIIF和DMAC體積 標準工作溶液 加入油性THF標準中間溶液添加量 μL DMAC添加量 ML 標準工作溶液中THF的濃度 mg/kg 0 0 300 0 1 12 288 0.O6 2 50 250 0.25 3 120 180 0.60 4 200 100 1.00 5 300 0 1.50 附 錄 B 氣相色譜法和氣相色譜-質譜法標準品譜圖 FID信號 異辛烷 1-辛烯 圖B.1 1-辛烯標準氣相色譜圖 FID信號 四氫呋喃 四氫吡喃 圖B.2 四氫呋喃標準氣相色譜圖 豐度 異辛烷 1-辛烯 圖B.3 1-辛烯氣相色譜-質譜總離子流(SIM)圖 豐度 四氫呋喃 四氫吡喃 圖B.4 四氫呋喃氣相色譜-質譜總離子流(SIM)圖