This International Standard describes two methods for the determination of free formaldehyde (HCHO) in polymer dispersions. The procedure has been evaluated using acrylic, acrylonitrile butadiene, carboxylated styrenebutadiene and vinyl acetate polymer dispersions. Both test methods may also be applicable to polymer dispersions of other compositions.<\/p>\n
Method A is the preferred method for polymer dispersions with a free-formaldehyde content higher than 10 mg\/kg. Method B is recommended if lower formaldehyde contents have to be determined or arbitration analyses have to be carried out.<\/p>\n
Both methods minimize changes in free-formaldehyde concentration that can result from changes in the physical or chemical properties of polymer dispersions.<\/p>\n
There are no known limitations to these methods when used in the manner described.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 3<\/td>\n | Plastics\ufffd\u2014 Polymer dispersions\ufffd\u2014 Determination of free formaldehyde <\/td>\n<\/tr>\n | ||||||
| 5<\/td>\n | Contents Page <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | Foreword <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | Plastics\ufffd\u2014 Polymer dispersions\ufffd\u2014 Determination of free formaldehyde 1\ufffd\ufffd\ufffd Scope 2\ufffd\ufffd\ufffd Normative references 3\ufffd\ufffd\ufffd Principle <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | 4\ufffd\ufffd\ufffd Interference 4.1\ufffd\ufffd\ufffd Method A 4.2\ufffd\ufffd\ufffd Method B 5\ufffd\ufffd\ufffd Reagents (methods\ufffdA and B) 5.1\ufffd\ufffd\ufffd Acetic acid 5.2\ufffd\ufffd\ufffd Ammonium acetate 5.3\ufffd\ufffd\ufffd Formaldehyde 5.4\ufffd\ufffd\ufffd 2,4-Pentanedione 5.5\ufffd\ufffd\ufffd Phosphoric acid solution 5.6\ufffd\ufffd\ufffd Potassium ferrocyanide trihydrate solution 5.7\ufffd\ufffd\ufffd Zinc sulfate heptahydrate solution 5.8\ufffd\ufffd\ufffd Sodium hydroxide <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | 5.9\ufffd\ufffd\ufffd Sodium phosphate, dibasic 5.10\ufffd\ufffd\ufffd Nash reagent 5.10.1\ufffd\ufffd\ufffd Transfer 5.10.2\ufffd\ufffd\ufffd Pipette 5.10.3\ufffd\ufffd\ufffd Transfer the Nash reagent to the post-column reactor reservoir (see 5.10.4\ufffd\ufffd\ufffd Degas the Nash reagent with a helium sparge. 5.11\ufffd\ufffd\ufffd Mobile phase and standard diluent 5.11.1\ufffd\ufffd\ufffd Transfer 5.11.2\ufffd\ufffd\ufffd Adjust the pH of the solution to 5.11.3\ufffd\ufffd\ufffd Prepare the standard diluent in the same manner. 5.11.4\ufffd\ufffd\ufffd Degas the mobile phase with a helium sparge. 5.12\ufffd\ufffd\ufffd Sample diluent 5.12.1\ufffd\ufffd\ufffd The sample diluent is prepared in the same way as the mobile phase described in 5.12.2\ufffd\ufffd\ufffd The final step of the diluent preparation requires a pH adjustment. Before this step, m… 5.13\ufffd\ufffd\ufffd Standard reference solution 5.13.1\ufffd\ufffd\ufffd Stock standard reference solution 5.13.2\ufffd\ufffd\ufffd Series of standard reference solutions <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 5.13.3\ufffd\ufffd\ufffd Frequency of preparation 6\ufffd\ufffd\ufffd Apparatus 6.1\ufffd\ufffd\ufffd Amber bottle 6.2\ufffd\ufffd\ufffd Sample filter 6.3\ufffd\ufffd\ufffd High-speed centrifuge 6.4\ufffd\ufffd\ufffd Low-speed centrifuge 6.5\ufffd\ufffd\ufffd Method A 6.5.1\ufffd\ufffd\ufffd Photoelectric colorimeter 6.5.2\ufffd\ufffd\ufffd Test tubes 6.6\ufffd\ufffd\ufffd Method B 6.6.1\ufffd\ufffd\ufffd HPLC system 6.6.1.1\ufffd\ufffd\ufffd Liquid chromatograph 6.6.1.2\ufffd\ufffd\ufffd Post-column reactor 6.6.1.3\ufffd\ufffd\ufffd Chromatographic column 6.6.1.4\ufffd\ufffd\ufffd Chromatographic guard column 6.6.1.5\ufffd\ufffd\ufffd Data system 6.6.1.6\ufffd\ufffd\ufffd Configuration of liquid chromatograph 6.6.1.7\ufffd\ufffd\ufffd Configuration of post-column reactor (PCR) <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 6.6.1.8\ufffd\ufffd\ufffd Operating conditions 6.6.2\ufffd\ufffd\ufffd Syringe 7\ufffd\ufffd\ufffd Procedure 7.1\ufffd\ufffd\ufffd Preparation of test solution 7.1.1\ufffd\ufffd\ufffd Dilution of test sample 7.1.2\ufffd\ufffd\ufffd Filtration 7.1.3\ufffd\ufffd\ufffd Centrifugation 7.1.4\ufffd\ufffd\ufffd Coagulation <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 7.2\ufffd\ufffd\ufffd Blank solution 7.3\ufffd\ufffd\ufffd Check test (method B) 7.3.1\ufffd\ufffd\ufffd Determine whether the system is working properly by injecting 7.3.2\ufffd\ufffd\ufffd The run time for the analysis is 7.4\ufffd\ufffd\ufffd Calibration 7.4.1\ufffd\ufffd\ufffd Method A 7.4.1.1\ufffd\ufffd\ufffd Two types of calibration are specified, depending on which test solution preparation p… 7.4.1.2\ufffd\ufffd\ufffd Measure the extinction coefficient of the standard solutions and prepare a calibration… 7.4.2\ufffd\ufffd\ufffd Method B 7.4.2.1\ufffd\ufffd\ufffd Inject 7.4.2.2\ufffd\ufffd\ufffd The area under the formaldehyde peak in the chromatogram is considered to be a quantit… 7.4.2.3\ufffd\ufffd\ufffd Measure the area of the formaldehyde peak (see <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 7.5\ufffd\ufffd\ufffd Determination of formaldehyde 7.5.1\ufffd\ufffd\ufffd Method A 7.5.2\ufffd\ufffd\ufffd Method B 7.5.2.1\ufffd\ufffd\ufffd Analyse the filtrate prepared in 7.5.2.2\ufffd\ufffd\ufffd Identify the formaldehyde peak on the chromatogram using the retention time. 7.5.2.3\ufffd\ufffd\ufffd Measure the formaldehyde peak area (see 7.5.2.4\ufffd\ufffd\ufffd Analyse the reagent blank (standard diluent) (see <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 8\ufffd\ufffd\ufffd Calculation 8.1\ufffd\ufffd\ufffd Calculate the mass fraction of formaldehyde in the diluted polymer dispersion, 8.2\ufffd\ufffd\ufffd Determine the mass fraction of formaldehyde in the test sample, 9\ufffd\ufffd\ufffd Precision for method B 9.1\ufffd\ufffd\ufffd Precision estimates <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 9.2\ufffd\ufffd\ufffd Repeatability 9.3\ufffd\ufffd\ufffd Reproducibility 9.4\ufffd\ufffd\ufffd Bias 10\ufffd\ufffd\ufffd Test report <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Plastics. Polymer dispersions. Determination of free formaldehyde<\/b><\/p>\n |