commiss direct eec june amend annex direct eec establish commun method analysi offici control feedingstuff commiss european commun regard treati establish european econom commun regard council direct eec juli introduct commun method sampl analysi offici control feedingstuff amend act access spain portug articl thereof commiss direct eec april establish commun method analysi offici control feedingstuff amend direct eec specifi method determin crude protein method amend reflect advanc scientif technic progress provis council direct eec novemb protect worker risk relat exposur chemic physic biolog agent work amend direct eec account prevent exposur mercuri compound remov mercuri mercur oxid list catalyst crude protein determin method measur provid direct accord opinion stand committe feedingstuff adopt direct articl annex direct eec amend accord annex direct articl member state bring forc law regul administr provis compli direct juli immedi inform commiss thereof member state adopt provis refer direct accompani refer time offici public procedur refer adopt member state articl direct address member state brussel june commiss rené steichen member commiss oj oj oj oj oj oj annex section annex determin crude protein replac determin crude protein purpos scope method make determin crude protein content feedingstuff basi nitrogen content determin kjeldahl method principl sampl digest sulfur acid presenc catalyst acid solut made alkalin sodium hydroxid solut ammonia distil collect measur quantiti sulfur acid excess titrat standard solut sodium hydroxid reagent potassium sulfat catalyst copper ii oxid cuo copper ii sulfat pentahydr cuso granul zinc sulfur acid ml sulfur acid mol sulfur acid mol methyl red indic dissolv mg methyl red ml ethanol sodium hydroxid solut technic grade ml sodium hydroxid solut ml sodium hydroxid solut mol granul pumic stone wash hydrochlor acid ignit acetanilid sucros nitrogen free apparatu apparatu suitabl perform digest distil titrat kjeldahl procedur procedur digest weigh sampl nearest transfer sampl flask digest apparatu add potassium sulfat quantiti catalyst copper ii oxid copper ii sulfat pentahydr ml sulfur acid granul pumic stone mix heat flask moder swirl time time mass carbon foam disappear heat intens liquid boil steadili heat adequ boil acid condens wall flask prevent side overh organ particl stick solut clear light green continu boil hour leav cool distil add carefulli water ensur complet dissolut sulfat cool add granul zinc place collect flask distil apparatu measur quantiti ml sulfur acid depend presum nitrogen content add drop methyl red indic connect digest flask condens distil apparatu immers end condens liquid contain collect flask depth cm observ slowli pour ml sodium hydroxid solut digest flask loss ammonia observ heat flask ammonia distil titrat titrad excess sulfur acid collect flask sodium hydroxid solut depend concentr sulfur acid end point reach blank test confirm reagent free nitrogen carri blank test digest distil titrat sucros place sampl calcul result content crude protein calcul formula vo volum ml naoh blank test volum ml naoh sampl titrat concentr mol sodium hydroxid mass sampl verif method repeat differ result parallel determin carri sampl exce absolut crude protein content rel higher crude protein content absolut crude protein content accuraci carri analysi digest distil titrat acetanilid presenc sucros acetanilid consum ml sulfur acid recoveri observ apparatu manual semi automat automat type apparatu requir transfer digest distil step transfer carri loss flask distil apparatu fit drop funnel add sodium hydroxid immedi connect flask condens pour liquid slowli side digest solidifi recomm determin larger amount sulfur acid product law nitrogen content volum sulfur acid collect flask reduc ml made ml water