commiss direct april lai commun method analysi offici control vinyl chlorid releas materi articl foodstuff eec commiss european commun regard treati establish european econom commun regard council direct eec januari approxim law member state relat materi articl vinyl chlorid monom intend contact foodstuff articl thereof articl direct eec lai materi articl pass foodstuff brought contact materi articl vinyl chlorid detect method limit detect mg kg articl limit control commun method analysi basi seri inter laboratori collabor trial method annex prove suffici accur reproduc adopt commun method measur provid direct accord opinion stand committe foodstuff adopt direct articl analysi offici control vinyl chlorid releas materi articl foodstuff perform method annex hereto articl member state bring forc law regul administr provis compli direct octob forthwith inform commiss thereof articl direct address member state brussel april commiss karl heinz narj member commiss oj annex determin vinyl chlorid releas materi articl foodstuff scope field applic method determin level vinyl chlorid foodstuff principl level vinyl chlorid vc foodstuff determin mean ga chromatographi quot headspac quot method reagent vinyl chlorid vc puriti greater dimethylacetamid dma free impur retent time vc intern standard condit test diethyl ether ci buten dma intern standard solut intern standard impur retent time vc condit test distil water deminer water equival puriti apparatu nb instrument piec apparatu mention special made specif usual laboratori apparatu assum ga chromatograph fit automat headspac sampler facil manual sampl inject flame ioniz detector detector mention point ga chromatograph column column permit separ peak air vc intern standard combin system signal obtain solut mg vc litr dma mg vc kg dma equal time background nois sampl phial flask fit silicon butyl rubber septa manual sampl techniqu take sampl headspac syring partial vacuum form insid phial flask manual techniqu phial pressur sampl larg phial recommend micro syring ga tight syring manual headspac sampl analyt balanc accur mg procedur caution vc hazard substanc ga ambient temperatur prepar solut carri ventil fume cupboard nb precaut ensur vc dma lost emploi manual sampl techniqu intern standard intern standard solut util procedur prepar standard vc solut solut concentr standard vc solut approxim mg kg accur weigh nearest mg suitabl glass vessel place quantiti ml dma weigh add dma quantiti vc liquid ga form inject slowli dma vc ad bubbl dma provid devic prevent loss dma reweigh nearest mg wait hour equilibrium attain intern standard emploi add intern standard concentr intern standard concentr standard vc solut intern standard solut prepar point standard solut refriger prepar dilut standard vc solut weigh amount concentr standard solut vc dilut volum weight dma intern standard solut concentr result dilut standard solut solut express mg litr mg kg prepar respons curv solut nb curv compris pair point repeat respons lower mg vc litr kg dma curv calcul point squar techniqu regress line calcul equat gt pic file quot quot gt recommend iso di gt pic file quot quot gt prepar seri phial add phial volum dilut standard vc solut dma intern standard solut dma final vc concentr duplic solut approxim equal mg litr mg kg dma phial total volum solut quantiti dilut standard vc solut ratio total volum ad vc solut quantiti ml dma intern standard solut exce seal phial proce point construct graph ordin valu show area height vc peak duplic solut ratio area height relev intern standard peak abscissa valu show vc concentr duplic solut valid prepar standard solut obtain point prepar standard vc solut solut repeat procedur point obtain dilut standard solut case concentr approxim equal mg vc mg vc kg dma intern standard solut add solut phial seal phial proce point valid solut averag ga chromatograph determin relat solut differ point respons curv obtain point solut valid differ greater reject solut obtain point repeat procedur begin prepar quot addit quot curv nb curv compris pair point curv calcul point squar techniqu indent gt pic file quot quot gt prepar sampl sampl foodstuff analyz repres foodstuff present analysi foodstuff mix reduc small piec mix sampl procedur prepar seri phial add phial quantiti sampl obtain foodstuff investig ensur equal quantiti ad phial close phial immedi add phial gram sampl ml prefer distil water deminer water equival puriti solvent note homogen foodstuff addit distil deminer water add phial volum dilut standard vc solut intern standard consid concentr vc ad phial equal mg kg foodstuff ensur total volum dma dma intern standard phial quantiti dilut standard vc solut addit dma ratio total volum solut quantiti foodstuff contain phial low phial seal phial proce point ga chromatograph determin agit phial avoid contact contain liquid septum obtain solut suspens sampl foodstuff homogen put seal phial waterbath hour ºc equilibrium attain agit sampl headspac phial util manual sampl techniqu care exerc obtain reproduc sampl syring pre warm temperatur sampl measur area height peak relat vc intern standard construct graph ordin show area height vc peak ratio area height vc peak area height intern standard peak abscissa valu show quantiti vc ad mg relat quantiti sampl foodstuff weigh phial kg measur abscissa intercept graph obtain concentr vc sampl foodstuff investig remov column excess dma method peak dma chromatogram result vc releas materi articl foodstuff investig express mg kg defin averag determin provid repeat criterion point satisfi confirm vc case vc releas materi articl foodstuff calcul point exce criterion articl council direct eec januari valu obtain determin confirm wai column stationari phase polar procedur continu chromatogram obtain evid overlap vc intern standard peak constitu sampl foodstuff ii detector micro electrolyt conduct detector iii mass spectrometri case molecular ion parent mass found ratio regard high probabl journal chromatograph scienc volum march page confirm presenc vc case doubt total mass spectrum check repeat differ result determin carri simultan rapid success sampl analyst condit exce mg vc kg foodstuff