The new national standard for sulfur dioxide in food (determination of sulfur dioxide in traditional Chinese medicine according to the Chinese Pharmacopoeia method) is supported by dedicated instruments: ST109A, ST109B1, ST109C, and ST109D series are all equipped with automatic reagent addition and automatic nitrogen blowing control functions (a first in China)!!!
Research and Development Background:
With the promulgation of the new national standard GB5009.34-2022 "Determination of Sulfur Dioxide in Food" , the detection methods for sulfur dioxide in food and Chinese medicinal materials in the Chinese Pharmacopoeia are now largely the same. Based on the new national standard and pharmacopoeia methods, Jinan Shengteng Technology has developed four dedicated testing instruments: ST109A, ST109B1, ST109C, and ST109D .
Features:
Heating method: Automatic far-infrared ceramic heating management system with automatic anti-dry-burning technology;
* Cooling method: The main unit has an integrated compressor design that automatically completes the internal circulation of cooling water, eliminating the need for an external chiller;
* Condenser design: National standard dedicated reflux condenser;
* Control system: Automatic heating technology, with selectable simmering and full-boiling heating modes; automatic timer from 0-999 minutes;
* Reagent addition: Reagents can be added automatically via a high-precision reagent dispensing pump, eliminating the need for manual operation;
* Nitrogen control: controlled by a rotor flow meter, range: 200-2000 ml/min;
| Comparison of New and Old National Standard Testing Methods for Determining Sulfur Dioxide in Food (First Method) |
| GB5009.34-2016 | GB5009.34-2022 (New National Standard) |
| Testing Methods | Titration Method | Titration Method Changed to: Acid-Base Titration Method, Added Second Method Spectrophotometry and Third Method Ion Chromatography. |
| Detection Range | This standard specifies the method for determining total sulfur dioxide in foods such as fruits, dried vegetables, rice flour, noodles, granulated sugar, edible fungi, and grape wine. | The first method is the acid-base titration method, suitable for the determination of sulfur dioxide in food; The second method is the spectrophotometry, direct extraction method applicable to white sugar and sugar products, starch and starch products, fresh wet noodle products, etc., for samples without oil and fat and colorless interference in the extraction solution, while nitrogen steam distillation extraction method is suitable for colored samples such as grape wine and brown sugar for the determination of sulfur dioxide; The third method is the ion chromatography method, suitable for the determination of sulfur dioxide in food. |
| Sample Preparation | 5g homogeneous sample (accurate to 0.001g, sampling amount can be adjusted based on content level), liquid samples can directly absorb 5.00mL~10.00mL sample; add water to 250ml; add 10ml of hydrochloric acid. | Take 20 g~100 g of solid or semi-solid sample (accurate to 0.01 g, sampling amount can be adjusted based on content level); take 20 mL (g)~200 mL (g) of liquid sample; add water to 20-500ml; add 10ml of 6mol/L hydrochloric acid. |
| Whether to Perform Nitrogen Distillation | No | Nitrogen Distillation, Flow Rate: 1.0-2.0L/min |
| Absorption Solution | 25mL Lead Acetate Absorption Solution | 50mL of 3% Hydrogen Peroxide Solution (First Method) |
| Distillation Method | Collect 200ml of distillate, then distill for 1 minute, rinse the device inserted into the absorption solution with a small amount of distilled water. | Heat the solution in the flask to boiling and maintain a gentle boil for 1.5h. |
| Titration Method | Add 10mL of hydrochloric acid and 1mL of starch indicator solution to the receiving flask in sequence, shake well, then titrate with iodine standard solution until the solution turns blue and remains unchanged for 30s. Perform a blank test simultaneously. | Cool the absorption solution and shake well, add 3 drops of 2.5 mg/mL methyl red ethanol indicator solution to the absorption solution, titrate with sodium hydroxide standard solution (0.01 mol/L) until the solution turns yellow and remains unchanged for 20 seconds, and perform a blank test simultaneously. |
| Detection Limit and Quantification Limit | When taking 5g of solid sample, the method's detection limit (LOD) is 3.0mg/kg, and the quantification limit is 10.0mg/kg; when taking 10mL of liquid sample, the method's detection limit (LOD) is 1.5mg/L, and the quantification limit is 5.0mg/L. | When using 0.01mol/L sodium hydroxide titration solution, for solid or semi-solid samples weighing 35g, the detection limit is 1mg/kg, and the quantification limit is 10mg/kg; for liquid samples taking 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 Pre-treatment), ST106K2 (Fully Automatic, Can Directly Output Test Results.) | ST109 Full Series (A is six-position, fully automatic model, directly outputs test results; B is six-position; C is eight-position, high cost-performance model; D is ion chromatography method, dedicated to water vapor distillation), all models are equipped with automatic acid addition and nitrogen control devices (A uses digital imported nitrogen controller, other models use rotor flow meters). The full series is compatible with testing sulfur dioxide in traditional Chinese medicine and herbal materials. |