{"id":3905,"date":"2025-09-04T11:10:27","date_gmt":"2025-09-04T03:10:27","guid":{"rendered":"https:\/\/www.pgeneral.com\/?p=3905"},"modified":"2025-09-04T11:10:27","modified_gmt":"2025-09-04T03:10:27","slug":"determination-of-lead-in-food-additive-sodium-pyrophosphate-flame-atomic-absorption-spectrometry","status":"publish","type":"post","link":"https:\/\/www.pgeneral.com\/pt\/applications\/determination-of-lead-in-food-additive-sodium-pyrophosphate-flame-atomic-absorption-spectrometry","title":{"rendered":"Determina\u00e7\u00e3o do chumbo no aditivo alimentar Pirofosfato de s\u00f3dio (espectrometria de absor\u00e7\u00e3o at\u00f4mica de chama)"},"content":{"rendered":"

1. Vista geral do m\u00e9todo<\/h2>\n
Ap\u00f3s a amostra ser tratada, os i\u00f3ns de chumbo formam um complexo com dietilditiocarbamato de s\u00f3dio (DDTC) sob certa condi\u00e7\u00e3o de pH. O complexo \u00e9 extra\u00eddo e separado com 4-metil-2-pentanono (MIBK), ent\u00e3o introduzido em um espectrometro de absor\u00e7\u00e3o at\u00f4mica. Ap\u00f3s atomiza\u00e7\u00e3o da chama, a absorb\u00e2ncia \u00e9 medida a um comprimento de onda de 283,3 nm. Dentro de uma certa gama de concentra\u00e7\u00f5es, o valor de absor\u00e7\u00e3o do chumbo \u00e9 proporcional ao seu conte\u00fado, e a quantifica\u00e7\u00e3o \u00e9 realizada em compara\u00e7\u00e3o com uma s\u00e9rie padr\u00e3o.<\/div>\n
\n

2. Instrumentos e Reagentes<\/h2>\n

2.1 Instrumentos e equipamento<\/h3>\n

2.1.1 Instrumentos de ensaio<\/h4>\n
\n
\n\n\n\n\n\n\n\n
Serie No.<\/th>\nNome<\/th>\nQuantidade<\/th>\nRequisitos T\u00e9cnicos<\/th>\nAcess\u00f3rios<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nEspetrofotometro de Absor\u00e7\u00e3o At\u00f4mica de Flame<\/td>\n1 conjunto<\/td>\n–<\/td>\nLead Hollow Cathode Lamp<\/td>\n<\/tr>\n
2<\/td>\nCompressor de ar<\/td>\n1 conjunto<\/td>\nPress\u00e3o de descarga estimada: 0,3 MPa<\/td>\n–<\/td>\n<\/tr>\n
3<\/td>\nGas de acetileno<\/td>\n1 cilindro<\/td>\nPureza \u2265 99,99%<\/td>\n–<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

2.1.2 Equipamento de pr\u00e9-tratamento de amostras<\/h4>\n
\n
\n\n\n\n\n\n\n\n\n\n\n
Serie No.<\/th>\nNome<\/th>\nQuantidade<\/th>\nRequisitos T\u00e9cnicos<\/th>\nAcess\u00f3rios<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nBalan\u00e7o electr\u00f3nico<\/td>\n1 conjunto<\/td>\nSensibilidade: 0,1 mg<\/td>\n–<\/td>\n<\/tr>\n
2<\/td>\nBeaker<\/td>\nV\u00e1rios<\/td>\nVolume: 150 ml<\/td>\n–<\/td>\n<\/tr>\n
3<\/td>\nPlata quente ajustada<\/td>\n1 conjunto<\/td>\nRango de temperatura: temperatura do quarto ~ 300[UNK]<\/td>\n–<\/td>\n<\/tr>\n
4<\/td>\nFunnel Separat\u00f3rio<\/td>\nV\u00e1rios<\/td>\nVolume: 250 ml<\/td>\n–<\/td>\n<\/tr>\n
5<\/td>\nMicropipeta<\/td>\n1 cada<\/td>\nRangos: 100 \u03bcL~1000 \u03bcL, 1000 \u03bcL~5000 \u03bcL<\/td>\n–<\/td>\n<\/tr>\n
6<\/td>\nTubo Colorim\u00e9trico<\/td>\nV\u00e1rios<\/td>\nVolume: 10 ml<\/td>\n–<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

2.2 Reagentes<\/h3>\n

2.2.1 Reagentes mentais<\/h4>\n
\n
\n\n\n\n\n\n\n\n\n\n\n\n
Serie No.<\/th>\nNome<\/th>\nRequisitos T\u00e9cnicos<\/th>\nObserva\u00e7\u00f5es<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\n4-Metil-2-pentanono (MIBK)<\/td>\nReagente Anal\u00edtico (AR)<\/td>\n–<\/td>\n<\/tr>\n
2<\/td>\n\u00c1gua de am\u00f4nia<\/td>\nReagente Anal\u00edtico (AR)<\/td>\n–<\/td>\n<\/tr>\n
3<\/td>\nSulfato de am\u00f4nio<\/td>\nReagente garantido (GR)<\/td>\n–<\/td>\n<\/tr>\n
4<\/td>\nCitrato de am\u00f4nio<\/td>\nReagente Anal\u00edtico (AR)<\/td>\n–<\/td>\n<\/tr>\n
5<\/td>\nDietilditiocarbamato de s\u00f3dio (DDTC)<\/td>\nReagente garantido (GR)<\/td>\n–<\/td>\n<\/tr>\n
6<\/td>\nBromotimol Azul<\/td>\nReagente Anal\u00edtico (AR)<\/td>\n–<\/td>\n<\/tr>\n
7<\/td>\n\u00c1cido n\u00edtrico<\/td>\nMOS Grade<\/td>\n–<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

2.2.2 Reagentes preparados<\/h4>\n
\n
\n\n\n\n\n\n\n\n\n\n\n
Serie No.<\/th>\nNome<\/th>\nM\u00e9todo de Prepara\u00e7\u00e3o<\/th>\nObserva\u00e7\u00f5es<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nAm\u00f4nia Water Solution (1 1)<\/td>\nMedir 50 ml de \u00e1gua de am\u00f4nia, adicion\u00e1-la a 50 ml de \u00e1gua e mistura bem.<\/td>\n–<\/td>\n<\/tr>\n
2<\/td>\nSolu\u00e7\u00e3o de Sulfato de Am\u00f4nio (300 g\/L)<\/td>\nPesar 30 g de sulfato de am\u00f4nio, dissolv\u00ea-lo na \u00e1gua e dilui-lo para 100 ml com \u00e1gua.<\/td>\n–<\/td>\n<\/tr>\n
3<\/td>\nSolu\u00e7\u00e3o de Citrato de Am\u00f4nio (250 g\/l)<\/td>\nPesar 25 g de citrato de am\u00f4nio, dissolv\u00ea-lo na \u00e1gua e dilui-lo para 100 ml com \u00e1gua.<\/td>\n–<\/td>\n<\/tr>\n
4<\/td>\nSolu\u00e7\u00e3o de dietildiocarbata de s\u00f3dio (DDTC) (50 g\/L)<\/td>\nPese 5 g de dietilditiocarbamato de s\u00f3dio, dissolva-o na \u00e1gua e dilui-o para 100 ml com \u00e1gua.<\/td>\n–<\/td>\n<\/tr>\n
5<\/td>\nSolu\u00e7\u00e3o de Indicador Azul de Bromotimol (1 g\/L)<\/td>\nPesar 0,1 g de azul de bromotimol, dissolv\u00ea-lo na \u00e1gua, e diluir para 100 ml com \u00e1gua, e ent\u00e3o misturar bem.<\/td>\n–<\/td>\n<\/tr>\n
6<\/td>\nSolu\u00e7\u00e3o de \u00e1cido n\u00edtrico (5 95)<\/td>\nMedir 50 ml de \u00e1cido n\u00edtrico, adicion\u00e1-lo a 950 ml de \u00e1gua e mistura bem.<\/td>\n–<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

2.3 Normas de refer\u00eancia<\/h3>\n

2.3.1 Solu\u00e7\u00e3o de a\u00e7\u00f5es<\/h4>\n
\n
\n\n\n\n\n\n
Serie No.<\/th>\nN\u00e3o.<\/th>\nNome<\/th>\nRequisitos T\u00e9cnicos<\/th>\nObserva\u00e7\u00f5es<\/th>\n<\/tr>\n<\/thead>\n
1<\/td>\nGSB G 62071-90<\/td>\nLead Standard Solution<\/td>\nConcentra\u00e7\u00e3o: 1000 \u03bcg\/ml<\/td>\nCentral Iron and Steel Research Institute, National Iron and Steel Materials Testing Center<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n

3. Calcula\u00e7\u00e3o dos resultados<\/h2>\n
O conte\u00fado de chumbo \u00e9 expresso como a fra\u00e7\u00e3o de massa\u00a0W<\/span>\u00a0de chumbo (Pb), em unidades de mg\/kg, calculada pela seguinte f\u00f3rmula:<\/div>\n
\"\"<\/div>\n
Onde:<\/div>\n
    \n
  • m1<\/span>= massa de chumbo na solu\u00e7\u00e3o de ensaio obtida da curva de trabalho, unidade: miligramas (mg);<\/li>\n
  • m0<\/span>\u00a0= massa de chumbo na solu\u00e7\u00e3o de ensaio em branco obtida da curva de trabalho, unidade: miligramas (mg);<\/li>\n
  • m<\/span>\u00a0= massa da amostra, unidade: grama (g).<\/li>\n<\/ul>\n

     <\/p>\n

    A m\u00e9dia aritm\u00e9tica dos resultados da determina\u00e7\u00e3o paralela \u00e9 considerada como o resultado final da determina\u00e7\u00e3o. A diferen\u00e7a absoluta entre os dois resultados de determina\u00e7\u00e3o paralela n\u00e3o deve exceder 1 mg\/kg.<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"

    1. Method Overview After the sample is treated, lead ions form a complex with sodium diethyldithiocarbamate (DDTC) under a certain pH condition. The complex is extracted and separated with 4-methyl-2-pentanone (MIBK), then introduced into an atomic absorption spectrometer. After flame atomization, the absorbance is measured at a wavelength of 283.3 nm. Within a certain concentration […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[36,73],"tags":[],"class_list":["post-3905","post","type-post","status-publish","format-standard","hentry","category-applications","category-food-and-drugs"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.pgeneral.com\/pt\/wp-json\/wp\/v2\/posts\/3905","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.pgeneral.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.pgeneral.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.pgeneral.com\/pt\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.pgeneral.com\/pt\/wp-json\/wp\/v2\/comments?post=3905"}],"version-history":[{"count":0,"href":"https:\/\/www.pgeneral.com\/pt\/wp-json\/wp\/v2\/posts\/3905\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.pgeneral.com\/pt\/wp-json\/wp\/v2\/media?parent=3905"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.pgeneral.com\/pt\/wp-json\/wp\/v2\/categories?post=3905"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.pgeneral.com\/pt\/wp-json\/wp\/v2\/tags?post=3905"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}