Special instruments for the new national standard food sulfur dioxide (Chinese Pharmacopoeia method for testing traditional Chinese medicine sulfur dioxide): ST109A, ST109B, ST109C, ST109D are all equipped with automatic reagent addition and automatic nitrogen blowing control functions (the first in the country)!!!
R&D Background:
With the promulgation of the new national standard GB5009.34-2022 "Determination of sulfur dioxide in food" , the determination methods of sulfur dioxide in food and sulfur dioxide in traditional Chinese medicine in the "Chinese Pharmacopoeia" are roughly the same. Jinan Shengtai Technology has developed four special testing instruments, ST109A, ST109B, ST109C, and ST109D , based on the new national standard and pharmacopoeia methods.
Features:
* Heating method: automatic far-infrared ceramic heating management system, automatic anti-dry burning technology;
* Cooling method: The host has a built-in compressor integrated design, which automatically completes the internal circulation of cooling water, without the need for an external chiller;
* Condenser design: National standard special reflux condenser;
* Control system: automatic heating technology, can set micro-boiling and full-boiling heating modes; automatic timing 0-999min;
* Reagent addition: Reagent addition can be completed automatically through a high-precision reagent filling pump without manual operation;
* Nitrogen control: rotor flowmeter control, range: 200-2000ml/min;
| Comparison of the new and old national standard test methods for the determination of sulfur dioxide in food (method 1) |
| GB5009.34-2016 | GB5009.34-2022 (new national standard) |
| Detection Methods | Titration | The titration method was changed to acid-base titration method, and the second method spectrophotometry and the third method ion chromatography were added. |
| Detection range | This standard specifies the determination method for total sulfur dioxide in foods such as preserved fruits, dried vegetables, rice noodles, vermicelli, sugar, edible fungi and wine. | The first method is acid-base titration, which is applicable to the determination of sulfur dioxide in food;
The second method is spectrophotometry. The direct extraction method is applicable to the determination of sulfur dioxide in samples without oil and fat, such as white sugar and white sugar products, starch and starch products, and raw wet noodle products, and the extract has no color interference. The nitrogen-filled distillation extraction method is applicable to the determination of sulfur dioxide in colored samples such as wine and brown sugar.
The third method is ion chromatography, which is suitable for the determination of sulfur dioxide in food. |
| Sample preparation | 5g uniform sample (accurate to 0.001g, the sampling amount can be determined according to the content), liquid sample can directly absorb 5.00mL~10.00mL sample; add 250ml of water; add 10ml of hydrochloric acid. | Take 20 g to 100 g of solid or semi-fluid sample (accurate to 0.01 g, the sampling amount can be determined according to the content); take 20 mL (g) to 200 mL (g) of liquid sample; add 20-500 ml of water; add 10 ml of 6 mol/L hydrochloric acid. |
| Whether to distill with nitrogen | no | Nitrogen distillation, flow rate: 1.0-2.0L/min |
| Absorption liquid | 25mL lead acetate absorption solution | 3% hydrogen peroxide solution 50mL (method 1) |
| Distillation method | Collect 200 ml of distillate, distill for another minute, and rinse the device inserted into the absorption liquid with a small amount of distilled water. | Heat the solution in the flask to boiling and keep it at a slight boil for 1.5 hours. |
| Titration method | Add 10 mL of hydrochloric acid and 1 mL of starch indicator solution to the removed iodine volumetric flask, shake well, and titrate with iodine standard solution until the solution turns blue and does not fade within 30 seconds. Perform a blank test at the same time. | Cool the absorption liquid and shake it evenly. Add 3 drops of 2.5 mg/mL methyl red ethanol solution as indicator to the absorption liquid. Titrate with sodium hydroxide standard solution (0.01 mol/L) until it turns yellow and does not fade within 20 seconds. Perform a blank test at the same time. |
| Limit of Detection and Limit of Quantitation | When taking 5g solid sample, the detection limit (LOD) of the method is 3.0mg/kg, and the quantification limit is 10.0mg/kg; when taking 10mL liquid sample, the detection limit (LOD) of the method is 1.5mg/L, and the quantification limit is 5.0mg/L. | When using 0.01mol/L sodium hydroxide titration solution, when the solid or semi-fluid sample weight is 35g, the detection limit is 1mg/kg and the quantification limit is 10mg/kg; when the liquid sampling volume is 50mL (g), the detection limit is 1mg/L (mg/kg) and the quantification limit is 6 mg/L (mg/kg). |
| Recommended product models | ST106-1RW (distillation pretreatment), ST106K2 (fully automatic, can directly output test results.) | The full range of ST109 (A is a six-digit, fully automatic model that directly outputs the test results; B is a six-digit; C is an eight-digit, cost-effective model; D is a special machine for ion chromatography steam distillation) is equipped with automatic acid addition and nitrogen control devices as standard (A uses a digital imported nitrogen controller, and other models use rotor flow meters). The full range is compatible with the detection of sulfur dioxide in traditional Chinese medicine and Chinese medicinal materials. |
