{"id":381259,"date":"2024-10-20T03:10:44","date_gmt":"2024-10-20T03:10:44","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/bs-iso-184472021\/"},"modified":"2024-10-26T05:45:54","modified_gmt":"2024-10-26T05:45:54","slug":"bs-iso-184472021","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/bsi\/bs-iso-184472021\/","title":{"rendered":"BS ISO 18447:2021"},"content":{"rendered":"

This document specifies a high performance liquid chromatography (HPLC) or ultra-high performance liquid chromatography (UHPLC) method for the determination of content of the four major theaflavins of tea.<\/p>\n

It is applicable to both leaf and instant black and oolong teas. The method is currently not validated for ready-to-drink (RTD) beverages.<\/p>\n

PDF Catalog<\/h4>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
PDF Pages<\/th>\nPDF Title<\/th>\n<\/tr>\n
2<\/td>\nNational foreword <\/td>\n<\/tr>\n
6<\/td>\nForeword <\/td>\n<\/tr>\n
7<\/td>\n1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Reagents
5.1 General <\/td>\n<\/tr>\n
8<\/td>\n5.1.8 20 % acetonitrile stabilizer solution.
5.1.9 Leaf\/infusion stabilizing solution.
5.2 HPLC mobile phases
5.3 Stock standard solutions
5.3.1 General <\/td>\n<\/tr>\n
9<\/td>\n5.3.2 Preparation of individual theaflavin stock standard solutions
5.4 Mixed standard solutions
5.5 Caffeine standard \u2014 Preparation of caffeine stock solution, corresponding to 2,00 mg\/ml <\/td>\n<\/tr>\n
10<\/td>\n6 Apparatus <\/td>\n<\/tr>\n
11<\/td>\n6.12 Data collection\/integration system.
7 Sampling
8 Preparation of test samples
9 Procedure
9.1 General
9.2 Determination of dry matter content <\/td>\n<\/tr>\n
12<\/td>\n9.3 Test portion
9.3.1 Instant tea
9.3.2 Leaf tea
9.4 Extraction of theaflavins
9.4.1 Instant tea
9.4.2 Leaf tea
9.5 Dilution <\/td>\n<\/tr>\n
13<\/td>\n9.6 Determination
9.6.1 General
9.6.2 Adjustment of the apparatus
9.6.3 HPLC analysis
9.6.4 Identification <\/td>\n<\/tr>\n
14<\/td>\n10 Calculation
10.1 General
10.2 Quantitation using theaflavin standards <\/td>\n<\/tr>\n
15<\/td>\n10.3 Quantitation using a caffeine standard and theaflavin RRFs <\/td>\n<\/tr>\n
16<\/td>\n11 Precision
11.1 Interlaboratory test
11.2 Repeatability
11.3 Reproducibility
12 Test report <\/td>\n<\/tr>\n
17<\/td>\nAnnex A (informative) Results of interlaboratory tests <\/td>\n<\/tr>\n
18<\/td>\nAnnex B (informative) Assessment of the purity of standards used in the RRF work <\/td>\n<\/tr>\n
19<\/td>\nAnnex C (informative) Typical HPLC chromatograms <\/td>\n<\/tr>\n
24<\/td>\nBibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

Tea. Determination of theaflavins in black tea. Method using high performance liquid chromatography<\/b><\/p>\n\n\n\n\n
Published By<\/td>\nPublication Date<\/td>\nNumber of Pages<\/td>\n<\/tr>\n
BSI<\/b><\/a><\/td>\n2021<\/td>\n26<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":381268,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[972,2641],"product_tag":[],"class_list":{"0":"post-381259","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-67-140-10","7":"product_cat-bsi","9":"first","10":"instock","11":"sold-individually","12":"shipping-taxable","13":"purchasable","14":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/381259","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/381268"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=381259"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=381259"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=381259"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}