This standard specifies the determination method of moisture and volatile matter content in vegetable oils and fats. Including vacuum oven method, air oven method, and hot plate method. This standard applies to vegetable oils and fats. GB/T 5528-1995 Determination of moisture and volatile matter content in vegetable oils and fats GB/T5528-1995 Standard download decompression password: www.bzxz.net

GB/T5528-1995
National Standard of the People's Republic of China
Method for determination of moisture and Volatile matter in vegetable oil and fatGB/T5528-1995
Replaces GB5528-85
1 Subject and Scope of Application
This standard specifies the method for determination of moisture and volatile matter in vegetable oil and fat. It includes vacuum oven method, air oven method and electric hot plate method. www.bzxz.net
The real oven method is the reference method, which is applicable to non-drying oil, semi-drying oil and drying oil; the air oven method is applicable to non-drying oil; the electric hot plate method is a rapid determination method. This standard is applicable to vegetable oil and fat.
2 Principle
Under the pressure and temperature conditions specified in this standard, the sample is dried to evaporate the moisture and volatile matter. The weight difference before and after drying is the moisture and volatile matter content of the oil and fat. 3 Reference standards
GB5524
Sampling and splitting method for testing vegetable oils
GB/T15687
Preparation of oil samples
4 Instruments and reagents
4.1 Analytical balance: sensitivity 0.0001g.
4.2 Vacuum oven: constant temperature ±1°C.
4.3 Decompression device: composed of vacuum pump (air volume 10L/min), drying bottle (with anhydrous calcium chloride), and glass tee.
4.4 Air oven: constant temperature ±1°C.
4.5 Electric heating plate: flat plate or trough type, constant temperature ±2.0°C. 4.6 Dryer: Φ300mm (with anhydrous magnesium perchlorate). 4.7 Weighing blood: aluminum (diameter 50mm, height 20mm) or 100mL beaker. 4.8 Desiccant: fresh anhydrous perchloric acid (chemically pure). Approved by the State Administration of Technical Supervision on August 17, 1995 and implemented on January 1, 1996
GB/T5528-1995
5 Sample preparation
5.1 Sampling and sub-sampling: in accordance with GB5524. 5.2 Samples: in accordance with GB/T15687.
6 Determination
6.1 Vacuum flask method (reference method)
6.1.1 Weigh 5g of sample (m) in a weighing dish (4.7) that has been weighed to a constant weight and shaken immediately, with an accuracy of 0.001g.
6.1.2 Place the sample in a vacuum flask (4.2) at 75±1℃ and tighten the door knob. 6.1.3 Start the vacuum pump of the decompression device (4.3) and tighten the door when the vacuum pressure in the real oven reaches 13.3 kPa (100 mmHg). Then start timing and dry for 1 hour. During the drying process, the vacuum pressure is maintained between 12.0 and 13.3 kPa (90 and 100 mmHg). 6.1.4 After the vacuum drying is completed, loosen all the knobs on the vacuum oven door and carefully rotate the glass tee to allow air to slowly enter the vacuum oven through the drying bottle (about 5 minutes) so that the vacuum pressure in the oven slowly returns to normal pressure. When restoring the pressure, avoid splashing the sample from the weighing blood. 6.1.5 Take out the sample and immediately put it into the dryer (4.6). Cool it to room temperature (more than 30 minutes) and weigh the weight after drying (m2) with an accuracy of 0.001g. 6.1.6 Repeat 6.1.2 to 6.1.5 for re-drying, the re-drying time is 30 minutes, until the difference between the two weights is less than 0.001g.
6.2 Air oven method
6.2.1 Weigh 10g of sample m, which is immediately shaken, in the constant weight blood sample (4.7) (m), accurate to 0.01g.
6.2.2 Place the sample in an oven (4.4) at 103±2℃ and dry for 60 minutes. 6.2.3 Take out the sample blood, immediately place it in a dryer (4.6), fully cool it to room temperature (more than 30 minutes), and weigh the weight after drying (m2), accurate to 0.001g. 6.2.4 Repeat 6.2.2 to 6.2.3 for re-drying, the re-drying time is 30 minutes, until the difference between the two weights is less than 0.002g. If the latter weight is greater than the former weight, the former weight shall prevail. 6.3 Hot plate method (quick method)
6.3.1 Pour about 20g of sample into a 100mL beaker, insert a thermometer, place it on the hot plate (4.5), and adjust the temperature of the hot plate so that the oil temperature reaches and remains within the range of 103±2℃. 6.3.2 Weigh about 20g of sample (m) and shake it immediately into two 100mL beakers (4.7) with constant weight and glass rods (m), accurate to 0.001g. 6.3.3 Place the sample on a hot plate at 103±2℃ and dry it for 20min. Stir it slowly with a glass rod during the drying process.
Approved by the State Administration of Technical Supervision on August 17, 1995, and implemented on January 1, 1996
GB/T5528-1995
6.3.4 Place the dried sample immediately in the dryer (4.6), cool it to room temperature (about 1 hour), and weigh the dried weight (m2) to an accuracy of 0.001g. 7 Calculation of results
7.1 Calculate the percentage of moisture and volatile matter according to the following formula: ml-m2×100
Moisture and volatile matter content (%)=\
Where: m is the weight of blood and sample before drying, g; m2 is the weight of blood sample and sample after drying, g; mo is the weight of blood sample, g.
7.2 Take the average of the two experimental results that meet the repeatability requirements, and use the average value to represent the moisture and volatile matter content of the sample.
7.3 The determination results shall indicate the determination method used. 7.4 Repeatability: In the same laboratory, the difference between two simultaneous or consecutive determination results shall not exceed 0.05%. Additional remarks:
This standard was proposed by the Ministry of Domestic Trade of the People's Republic of China. This standard is under the jurisdiction of the Ministry of Domestic Trade of the People's Republic of China. This standard was drafted by the Beijing Institute of Grain Science. The main drafter of this standard was Zhang Chengxiang.
Approved by the State Administration of Technical Supervision on August 17, 1995 and implemented on January 1, 1996
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.