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protein + formic acid +

protein + formic acid +, Total:231 items.

In the international standard classification, protein + formic acid + involves: Organic chemicals, General methods of tests and analysis for food products, Milk and milk products, Laboratory medicine, Beverages, Food products in general, Animal feeding stuffs, FOOD TECHNOLOGY, Spices and condiments. Food additives, Adhesives, Products of the chemical industry, Paint ingredients, Protection against crime, Medical equipment, Medical sciences and health care facilities in general, Meat, meat products and other animal produce.

API - American Petroleum Institute, protein + formic acid +

API PUBL 4647-1997 Brain Glial Fibrillary Acidic Protein (GFAP) as a Marker of Neurotoxicity During Inhalation Exposure to Toluene

Henan Provincial Standard of the People's Republic of China, protein + formic acid +

DB41/T 1040-2015 methanol protein
DB41/T 1089-2015 Shopping mall stew cooking skills egg white turtle stew

Danish Standards Foundation, protein + formic acid +

DS/CEN/TS 15633-2:2013 Foodstuffs - Detection of food allergens by immunological methods - Part 2: Quantitative determination of hazelnut with an enzyme immunoassay using monoclonal antibodies and bicinchoninic acid-protein detection
DS/ISO 5739:2003 Caseins and caseinates - Determination of contents of scorched particles and of extraneous matter
DS/ISO 13875:2007 Liquid milk - Determination of acid-soluble beta-lactoglobulin content - Reverse-phase HPLC-method

RU-GOST R, protein + formic acid +

GOST R 51470-1999 Caseins and caseinates. Method for determination of protein content
GOST 31978-2012 Caseins and caseinates. Method for determination of pH
GOST R 51467-1999 Caseins and caseinates. Method for determination of pH
GOST R 51464-1999 Caseins and caseinates. Method for determination of water content
GOST R 51465-1999 Caseins and caseinates. Determination of scorched particles content
GOST R 52993-2008 Caseins and caseinates. Determination of moisture content (Reference method)
GOST R 51454-1999 Caseins and caseinates. Method of determination of nitrate and nitrite contents
GOST R 51463-1999 Rennet caseins and caseinates. Method for determination of ASH content
GOST R 51469-1999 Caseins and caseinates. Photometric method for determination of lactose content
GOST R 51468-1999 Caseins. Method for determination of free acidity
GOST 34132-2017 Meat and meat products. Determination of amino acids composition of animal protein

European Committee for Standardization (CEN), protein + formic acid +

PD CEN/TS 15633-2:2013 Foodstuffs - Detection of food allergens by immunological methods - Part 2: Quantitative determination of hazelnut with an enzyme immunoassay using monoclonal antibodies and bicinchoninic acid-protein detection
EN ISO 23319:2022 Cheese and processed cheese products, caseins and caseinates - Determination of fat content - Gravimetric method (ISO 23319:2022)

CZ-CSN, protein + formic acid +

CSN 57 0111-5-2002 Testing methods for casein and caseinates - Determination of protein content
CSN 57 0111-8-2002 Testing methods for casein and caseinates - Determination of titratable acidity
CSN 57 0111-12-2002 Testing methods for casein and caseinates - Determination of pH
CSN 57 0111-1-2002 Testing methods for casein and caseinates - General regulations
CSN 57 0111-3-2002 Testing methods for casein and caseinates - Determination of moisture
CSN 57 0111-7-2002 Testing methods for casein and caseinates - Determination of ash
CSN 570111-5-2002 Testing methods for casein and caseinates - Determination of protein content
CSN 57 0111-2-2002 Testing methods for casein and caseinates - Methods of samphng of Chemical analysis
CSN 570111-8-2002 Testing methods for casein and caseinates - Determination of titratable acidity
CSN 570111-1-2002 Testing methods for casein and caseinates - General regulations
CSN 570111-3-2002 Testing methods for casein and caseinates - Determination of moisture
CSN 570111-7-2002 Testing methods for casein and caseinates - Determination of ash

Korean Agency for Technology and Standards (KATS), protein + formic acid +

KS H ISO 5549:2006 Caseins and caseinates－Determination of protein content(Reference method)
KS H ISO 5549-2006(2016) Caseins and caseinates－Determination of protein content(Reference method)
KS H ISO 5549:2021 Caseins and caseinates — Determination of protein content(Reference method)
KS H ISO 5739-2006(2016) Caseins and caseinates－Determination of scorched particles content
KS H ISO 5546-2006(2016) Caseins and caseinates－Determination of pH(Reference method)
KS H ISO 5546:2021 Caseins and caseinates — Determination of pH(Reference method)
KS H ISO 5739:2021 Caseins and caseinates — Determination of scorched particles content
KS H ISO 5550-2007(2021) Caseins and caseinates－Determination of moisture content(Reference method)
KS H ISO 5546:2006 Caseins and caseinates－Determination of pH(Reference method)
KS H ISO 5550:2007 Caseins and caseinates－Determination of moisture content(Reference method)
KS H ISO 5548:2006 Caseins and caseinates－Determination of lactose content－Photometric method
KS H ISO 5545:2006 Rennet caseins and caseinates－Determination of ash(Reference method)
KS H ISO 5550-2007(2012) Caseins and caseinates－Determination of moisture content(Reference method)
KS H ISO 5548:2020 Caseins and caseinates－Determination of lactose content－Photometric method
KS H ISO 5545:2021 Rennet caseins and caseinates —Determination of ash(Reference method)
KS H ISO 5545-2006(2016) Rennet caseins and caseinates－Determination of ash(Reference method)
KS H ISO 5739:2006 Caseins and caseinates－Determination of scorched particles content
KS H ISO 8195:2001 Caseins and caseinates－Determination of nitrate and nitrite contents－Method by cadmium reduction and spectrometry
KS H ISO 8195:2006 Caseins and caseinates－Determination of nitrate and nitrite contents－Method by cadmium reduction and spectrometry
KS H ISO 5543-2006(2016) Caseins and caseinates－Determination of fat content－Gravimetric method(Reference method)
KS H ISO 5543:2006 Caseins and caseinates－Determination of fat content－Gravimetric method(Reference method)
KS H ISO 5543:2021 Caseins and caseinates — Determination of fat content — Gravimetric method(Reference method)
KS H ISO 5547:2006 Caseins－Determination of free acidity(Reference method)
KS H ISO 5547:2021 Caseins — Determination of free acidity(Reference method)
KS H ISO 5547-2006(2016) Caseins－Determination of free acidity(Reference method)

International Organization for Standardization (ISO), protein + formic acid +

ISO 5549:1978 Caseins and caseinates; Determination of protein content (Reference method)
ISO 5546:1979 Caseins and caseinates; Determination of pH (Reference method)
ISO 5550:2006 Caseins and caseinates - Determination of moisture content (Reference method)
ISO 5550:2006|IDF 78:2006 Caseins and caseinates — Determination of moisture content (Reference method)
ISO 5550:1978 Caseins and caseinates; Determination of water content (Reference method)
ISO 5739:1983 Caseins and caseinates; Determination of scorched particles content
ISO 5546:2010 Caseins and caseinates - Determination of pH (Reference method)
ISO 5546:2010 | IDF 115:2010 Caseins and caseinates — Determination of pH (Reference method)
ISO 5546:2010|IDF 115:2010 Determination of pH value of casein and caseinate (standard method)
ISO 5548:2004 Caseins and caseinates - Determination of lactose content - Photometric method
ISO 5548:2004|IDF 106:2004 Caseins and caseinates — Determination of lactose content — Photometric method
ISO 5548:1980 Caseins and caseinates; Determination of lactose content; Photometric method
ISO 5545:2008 Rennet caseins and caseinates - Determination of ash (Reference method)
ISO 5550:2006 | IDF 78:2006 Caseins and caseinates — Determination of moisture content (Reference method)
ISO 5548:2004 | IDF 106:2004 Caseins and caseinates — Determination of lactose content — Photometric method
ISO 5545:2008|IDF 90:2008 Determination of abomasal casein and caseinate ash (reference method)
ISO 5545:2008 | IDF 90:2008 Rennet caseins and caseinates — Determination of ash (Reference method)
ISO 5739:2003 Caseins and caseinates - Determination of contents of scorched particles and of extraneous matter
ISO 5739:2003 | IDF 107:2003 Caseins and caseinates — Determination of contents of scorched particles and of extraneous matter
ISO 5739:2003|IDF 107:2003 Determination of casein and caseinate coke particles and foreign matter content
ISO 5543:2004 | IDF 127:2004 Caseins and caseinates — Determination of fat content — Gravimetric method (Reference method)
ISO 8195:1987 Caseins and caseinates; Determination of nitrate and nitrite contents; Method by cadmium reduction and spectrometry
ISO 5543:2004 Caseins and caseinates - Determination of fat content - Gravimetric method (Reference method)
ISO 5543:1986 Caseins and caseinates; Determination of fat content; Gravimetric method (Reference method)
ISO 5543:2004|IDF 127:2004 Gravimetric method for determination of fat content in casein and caseinate (reference method)
ISO 5547:2008 Caseins - Determination of free acidity (Reference method)
ISO 5547:2008|IDF 91:2008 Caseins — Determination of free acidity (Reference method)
ISO 5547:1978 Caseins; Determination of free acidity (Reference method)
ISO 5547:2008 | IDF 91:2008 Caseins — Determination of free acidity (Reference method)
ISO 23319:2022 | IDF 250 Cheese and processed cheese products, caseins and caseinates — Determination of fat content — Gravimetric method
ISO 23319:2022 | IDF 250:2022 Cheese and processed cheese products, caseins and caseinates — Determination of fat content — Gravimetric method
ISO 23319:2022 Cheese and processed cheese products, caseins and caseinates — Determination of fat content — Gravimetric method
ISO 5545:1978 Rennet caseins and caseinates; Determination of ash (Reference method)

KR-KS, protein + formic acid +

KS H ISO 5549-2021 Caseins and caseinates — Determination of protein content(Reference method)
KS H ISO 5546-2021 Caseins and caseinates — Determination of pH(Reference method)
KS H ISO 5739-2021 Caseins and caseinates — Determination of scorched particles content
KS H ISO 5548-2020 Caseins and caseinates－Determination of lactose content－Photometric method
KS H ISO 5545-2021 Rennet caseins and caseinates —Determination of ash(Reference method)
KS H ISO 8195-2001 Caseins and caseinates－Determination of nitrate and nitrite contents－Method by cadmium reduction and spectrometry
KS H ISO 5543-2021 Caseins and caseinates — Determination of fat content — Gravimetric method(Reference method)
KS H ISO 5547-2021 Caseins — Determination of free acidity(Reference method)

HU-MSZT, protein + formic acid +

AT-ON, protein + formic acid +

ONORM DIN 10454-1993 Determination of protein content of caseins and caseinates - Reference method
ONORM DIN 10456-1993 Determination of pH of caseins and caseinates - Reference method
ONORM DIN 10453-1993 Determination of water content of caseins and caseinates - Reference method

国家药监局, protein + formic acid +

YY/T 1216-2020 Alpha-fetoprotein assay kit

Lithuanian Standards Office , protein + formic acid +

LST ISO 5549:2001 Caseins and caseinates. Determination of protein content (Reference method) (identical ISO 5549:1978)
LST ISO 5548:2004 Caseins and caseinates. Determination of lactose content. Photometric method (idt ISO 5548:2004)
LST ISO 5546:2010 Caseins and caseinates - Determination of pH (Reference method) ( ISO 5546:2010, identical)
LST ISO 5739:2003 Caseins and caseinates. Determination of contents of scorched particles and of extraneous matter (idt ISO 5739:2003)
LST ISO 5545:2008 Rennet caseins and caseinates - Determination of ash (Reference method) (ISO 5545:2008, identical)
LST ISO 5543:2004 Caseins and caseinates. Determination of fat content. Gravimetric method (Reference method) (idt ISO 5543:2004)
LST ISO 5547:2008 Caseins - Determination of free acidity (Reference method) (ISO 5547:2008, identical)

British Standards Institution (BSI), protein + formic acid +

BS 6248-11:1987 Caseins and caseinates. Method for determination of nitrate and nitrite contents
BS ISO 5550:2006 Caseins and caseinates - Determination of moisture content (Reference method)
BS ISO 5546:2010 Caseins and caseinates - Determination of pH (Reference method)
BS ISO 5548:2004 Caseins and caseinates - Determination of lactose content - Photometric methods
BS ISO 5545:2008 Rennet caseins and caseinates - Determination of ash (Reference method)
BS ISO 5739:2003 Caseins and caseinates - Determination of contents of scorched particles and of extraneous matter
BS ISO 5543:2004 Caseins and caseinates - Determination of fat content - Gravimetric method (reference method)
BS ISO 5547:2008 Caseins - Determination of free acidity (Reference method)
20/30376375 DC BS ISO 23319. Cheese and processed cheese products, caseins and caseinates. Determination of fat content. Gravimetric method
BS EN ISO 23319:2022 Tracked Changes. Cheese and processed cheese products, caseins and caseinates. Determination of fat content. Gravimetric method

German Institute for Standardization, protein + formic acid +

DIN ISO 5546:2020-12 Caseins and caseinates - Determination of pH (Reference method) (ISO 5546:2010)
DIN ISO 5550:2020-12 Caseins and caseinates - Determination of moisture content (Reference method) (ISO 5550:2006)
DIN ISO 5545:2020-12 Rennet caseins and caseinates - Determination of ash (Reference method) (ISO 5545:2008)
DIN ISO 5546:2020 Caseins and caseinates - Determination of pH (Reference method) (ISO 5546:2010)
DIN ISO 5550:2020 Caseins and caseinates - Determination of moisture content (Reference method) (ISO 5550:2006)
DIN ISO 5545:2020 Rennet caseins and caseinates - Determination of ash (Reference method) (ISO 5545:2008)
DIN 10450:1983-03 Determination of free acidity of caseins; reference method
DIN EN ISO 23319:2023-01 Cheese and processed cheese products, caseins and caseinates - Determination of fat content - Gravimetric method (ISO 23319:2022); German version EN ISO 23319:2022
DIN EN ISO 23319:2023 Cheese and processed cheese products, caseins and caseinates - Determination of fat content - Gravimetric method (ISO 23319:2022)
DIN 10454:1983 Determination of protein content of caseins and caseinates; reference method

Association Francaise de Normalisation, protein + formic acid +

NF V04-384*NF ISO 5545:2008 Rennet caseins and caseinates - Determination of ash (Reference method).
NF V04-388*NF ISO 5548:2008 Caseins and caseinates - Determination of lactose content - Photometric method.
NF V04-389:1985 Caseins and caseinates. Determination of scorched particles content.
NF ISO 5546:2010 Caséines et caséinates - Détermination du pH (Méthode de référence)
NF V04-387:1985 Caseins and caseinates. Determination of protein content (reference method).
NF ISO 5548:2008 Caséines et caséinates - Détermination de la teneur en lactose - Méthode photométrique
NF ISO 5550:2007 Caséines et caséinates - Détermination de la teneur en humidité (méthode de référence)
NF ISO 5545:2008 Caséines présure et caséinates - Détermination des cendres (Méthode de référence)
NF V04-382:1988 Caseins and caseinates. Determination of fat content. Gravimetric method (reference method).
NF V04-390:1988 Caseins and caseinates. Determination of nitrate and nitrite contents. Method by cadmium reduction and spectrometry.
NF V04-382:2008 Caseins and caseinates - Determination of fat content - Gravimetric method (Reference method).
NF EN ISO 23319:2022 Fromages et fromages fondus, caséines et caséinates - Détermination de la teneur en matière grasse - Méthode gravimétrique
NF V04-386*NF ISO 5547:2008 Caseins - Determination of free acidity (Reference method)
NF V04-386:1985 Caseins. Determination of free acidity (reference method).
NF ISO 5547:2008 Caséines - Détermination de l'acidité libre (Méthode de référence)
NF V04-558*NF EN ISO 23319:2022 Cheese and processed cheese products, caseins and caseinates - Determination of fat content - Gravimetric method
NF V04-385*NF ISO 5546:2010 Caseins and caseinates - Determination of pH (Reference method).
NF V04-385:1985 Caseins and caseinates. Determination of pH (reference method).
NF V04-383*NF ISO 5550:2007 Caseins and caseinates - Determination of moisture content - (Reference method).
NF V04-383:1985 Caseins and caseinates. Determination of water content (reference method).
NF V04-388:1985 Caseins and caseinates. Determination of lactose content. Photometric method.
NF V04-384:1985 Rennet caseins and caseinates. Determination of ash (reference method).

International Dairy Federation (IDF), protein + formic acid +

IDF 90-2008 Rennet caseins and caseinates - Determination of ash (Reference method)
IDF 78-2006 Caseins and caseinates. Determination of moisture content (Reference method)
IDF 107-2003 Caseins and caseinates - Determination of contents of scorched particles and of extraneous matter
IDF 91-2008 Caseins - Determination of free acidity (Reference method)
IDF 178-2005 Liquid milk - Determination of acid-soluble β-lactoglobulin content - Reverse-phase HPLC method

IX-FAO, protein + formic acid +

CAC/RCP 64-2008(En) Production of Acid Hydrolyzed Vegetable Protein

IN-BIS, protein + formic acid +

IS 11888-1987
IS 11963-1987
IS 11962-1987
IS 850-1994 Natural sour (lactic)casein for glue manufacture-specification
IS 8678-1977
IS 7203-1973
IS 11964-1987

Professional Standard - Light Industry, protein + formic acid +

QB/T 3800-1999 Food additive.Sodium caseinate

Professional Standard - Business, protein + formic acid +

SB 10338-2000 Acid hydrolyzed vegetable protein seasoning

Professional Standard - Agriculture, protein + formic acid +

GB 10797-1989 Food Additive Sodium Caseinate
SB/T 10338-2000 Acid Hydrolyzed Vegetable Protein Flavoring Liquid
2157药典二部-2015 Part I Twelve Drawings of Protamine Sulfate
2251药典二部-2020 Part I Twelve Drawings of Protamine Sulfate
1779药典二部-2010 Part I Twelve Drawings of Protamine Sulfate
2389药典二部-2010 Appendix XII J Protamine Sulfate Bioassay
601药典第一增补本-2010 Protamine Sulfate Injection Revised by Part II
2158药典二部-2015 Part I Twelve Drawings of Protamine Sulfate Injection
2252药典二部-2020 Part I Twelve Drawings of Protamine Sulfate Injection
1780药典二部-2010 Part I Twelve Drawings of Protamine Sulfate Injection
649药典化学药和生物制品卷-2010 Chapter IX Endocrine System Drugs Section 2 Androgen and Anabolic Steroid 2. Anabolic Steroid Nandrolone Decanoate
192药典三部-2010 Appendix VI VIS Determination of Glycine Content in Human Immunoglobulin
648药典化学药和生物制品卷-2010 Chapter IX Endocrine System Drugs Section 2 Androgen and Anabolic Steroids 2. Anabolic Steroid Nandrolone Phenylpropionate
156药典四部-2020 1200 Bioactivity assay 1213 Protamine sulfate bioassay
168药典四部-2015 1200 Bioactivity assay 1213 Protamine sulfate bioassay
NY/T 2694-2015 Determination of complexation (chelation) strengths of manganese-amino acids and manganese-proteinates as feed additives
244药典三部-2020 Content Determination Method 3123 Determination of Glycine Content in Human Immunoglobulin
217药典四部-2015 3100 Content Determination Method 3123 Determination Method of Glycine Content in Human Immunoglobulin
205药典四部-2020 3100 Content Determination Method 3123 Determination Method of Glycine Content in Human Immunoglobulin
179药典三部-2010 Appendix Ⅵ ⅥE Histamine Method for Determination of Free Histamine Phosphate in Human Immunoglobulin
26兽药产品说明书范本第一册-2013 Instructions for Wuhua Ganbing Youyejia Baitou Ni to Folic Acid Tablets

Group Standards of the People's Republic of China, protein + formic acid +

T/WSJD 12-2020 plant protein drink plant yogurt
T/ZZB 1826-2020 Food nutrition enhancer casein phosphpeptide
T/ZZB 2172-2021 Soy protein-based wood adhesive without formaldehyde
T/QGCML 1839-2023 Technical specifications for testing sodium carbonate residue in silk fibroin membranes
T/CPMA 023-2020 Determination of N-methylcarbamoylatedhaemoglobin in blood by liquid chromatography-tandem mass spectrometry
T/LNIQA 010-2023 Determination of methylselenocysteine and selenomethionine in selenium-enriched foods

Professional Standard - Nuclear Industry, protein + formic acid +

EJ/T 952-1995 Alpha-fetoprotein radioimmunoassay kit

农业农村部, protein + formic acid +

NY/T 3801-2020 Determination of acid-soluble protein in feed ingredients
NY/T 3655-2020 Determination of calcium N-hydroxymethylmethionine in feed
NY/T 3802-2020 Determination of complex (chelate) strength of amino acid zinc and protein zinc in feed additives

Professional Standard - Medicine, protein + formic acid +

YY/T 1216-2013 Alpha-fetoprotein quantitative labelling immunoassay kit
YY/T 1817-2022
YY/T 1162-2009 Alpha-fetoprotein quantitative detection reagent(Kit) (Chemiluminescent Immunoassay)
YY/T 1590 Heart-type fatty acid binding protein assay kit (immunoturbidimetric method)

国家食品药品监督管理局, protein + formic acid +

YY/T 1594-2018 Human anti-thyroglobulin antibody assay kit

IX-EU/EC, protein + formic acid +

83/417/EEC-1983 Council Directive on the Approximation of the Laws of the Member States Relating to Certain Lactoproteins (Caseins and Caseinates) Intended for Human Consumption

RO-ASRO, protein + formic acid +

SR ISO 5545:1996 Rennet caseins and caseinates - Determination of ash (Reference method)
SR ISO 5549:1996 Caseins and caseinates - Determination of protein content (Reference method)

AENOR, protein + formic acid +

UNE 64062:1978 MIXED FEEDS AND RAW MATERIALS. EVALUATION OF RAW PROTEIN SOLUBILIZED BY PEPSINE AND CLORHYDRIC ACID.
UNE 64063:1978 MIXED FEEDS AND RAW MATERIAL. DETERMINATION OF THE ACIDITY OF PEPSINE.

CU-NC, protein + formic acid +

NC 26-125-1985 Drugs. Protamine Sulphate Determination of Biological Power
NC 26-75-17-1985 Drugs. Protamine Sulphate, Injection Quality Specifications

ES-UNE, protein + formic acid +

UNE-EN ISO 23319:2022 Cheese and processed cheese products, caseins and caseinates - Determination of fat content - Gravimetric method (ISO 23319:2022)

Professional Standard - Chemical Industry, protein + formic acid +

HG/T 2281-2014 Sodium formaldehyde sulfoxylate
HG/T 2281-2006 Rongalite
HG 2281-1992 Sodium bisulfite formaldehyde (carved white block)

Professional Standard - Public Safety Standards, protein + formic acid +

GA/T 819-2009 Analytical method of acid dyes on the protein fibers

Fujian Provincial Standard of the People's Republic of China, protein + formic acid +

DB35/T 1374-2013 Amino acid balanced low protein compound feed for pigs

General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China, protein + formic acid +

GB/T 18868-2002 Method for determination of moisture,crude protein,crude fat,crude fibre,lysine and methinione in feeds--Near infrared reflectance spectroscopy
GB 31617-2014 National Food Safety Standard Food Nutrient Enhancer Casein Phosphopeptide
GB/T 28715-2012 Determination of acidic and neutral protease activity in feed additives.Spetrophotometric method

American National Standards Institute （ANSI), protein + formic acid +

ANSI/NCCLS H8-A 2-1997 Abnormal Hemoglobin Using Cellulose Acetate Electrophoresis, Detection of

CH-SNV, protein + formic acid +

SN 210 100-1987 Technical drawings - Sizes and layout of drawing sheets

VN-TCVN, protein + formic acid +

TCVN 8766-2011 Milk and milk products.Determination of protein content.Acid orange 12 dye-binding method

国家药品监督管理局, protein + formic acid +

YY/T 1590-2018 Heart-type fatty acid binding protein assay kit (immunoturbidimetric method)

National Health Commission of the People's Republic of China, protein + formic acid +

GB 1886.212-2016 National Food Safety Standard Food Additive Sodium Caseinate (also known as Sodium Caseinate)

ES-AENOR, protein + formic acid +

UNE 53-425 Pt.1-1988

工业和信息化部, protein + formic acid +

HG/T 5506-2018 White polyethylene terephthalate (PET) reflective film

Hebei Provincial Standard of the People's Republic of China, protein + formic acid +

DB13/T 1091-2009 Determination of acid protease activity in enzyme preparations for feed - spectrophotometric method

Jilin Provincial Standard of the People's Republic of China, protein + formic acid +

DB22/T 1819-2013 Spectrophotometric method for the determination of acid protease activity in enzyme preparations for feed