Device and a method for preparing analysis samples using selective modes of vibrational oscillations and centrifugal rotations

Abstract

A device provides selective modes of vibrational oscillations and centrifugal rotations for preparing analysis samples. The device includes a base, an elastic connection body, a group of a synchronous unidirectional bearing inner ring and a synchronous unidirectional bearing outer ring, a group of an eccentric unidirectional bearing inner ring and an eccentric unidirectional bearing outer ring, and a synchronous fixed ring and a motor on the base. The eccentric unidirectional bearing outer ring is connected to a sample plate for holding the analysis samples.

Claims

1. An analytical sample preparation device, comprising: a base (1); an elastic connection body (5); a group of a synchronous unidirectional bearing inner ring (41) and a synchronous unidirectional bearing outer ring (42); a group of an eccentric unidirectional bearing inner ring (61) and an eccentric unidirectional bearing outer ring (62); and a synchronous fixed ring (2) and a motor (31) on the base (1), wherein the motor (31) is positioned within the synchronous fixed ring (2), wherein one end of the synchronous fixed ring (2) is fixed to the synchronous unidirectional bearing inner ring (41), wherein the synchronous unidirectional bearing outer ring (42) is connected to a lower end of the elastic connection body (5), wherein the eccentric unidirectional bearing inner ring (61) is connected with an eccentric shaft (32) extending from the motor (31), wherein the eccentric unidirectional bearing outer ring (62) is fixed to an eccentric shaft sleeve (9) that is fixed to a sample tray (7) and an upper end of the elastic connection body (5), wherein the eccentric shaft sleeve (9), the eccentric shaft (32), the eccentric unidirectional bearing inner ring (61), and the eccentric unidirectional bearing outer ring (62) have their center of mass disposed on a line extended from a center line of the motor (31), wherein the eccentric unidirectional bearing inner ring (61) and the eccentric unidirectional bearing outer ring (62) are configured to only rotate in direction A, wherein the synchronous unidirectional bearing outer ring (41) and the synchronous unidirectional bearing outer ring (42) are configured to only rotate in a direction opposite to direction A.

2. The analytical sample preparation device of claim 1, wherein the eccentric shaft (32) and the line extended from the center line of the motor (31) define an angle from 1 to 10 therebetween.

3. The analytical sample preparation device of claim 1, wherein an upper end of the elastic connection body (5) is connected with a lower end of the eccentric shaft sleeve (9), wherein the sample tray (7) is fixedly connected to the upper end of the eccentric shaft sleeve (9).

4. The analytical sample preparation device of claim 1, wherein direction A is clockwise or counterclockwise.

5. A method for preparing analytical samples using the analytical sample preparation device recited in claim 1, comprising: 1) placing a sample tube containing a sample and an extract into the sample tray (7); 2) setting the motor (31) to rotate in direction A for a first predetermined time, wherein the motor (31) drives the eccentric unidirectional bearing inner ring (61) to rotate relative to the eccentric unidirectional bearing outer ring (62), which causes the elastic connection body (5) to drive the sample tube to oscillate, thereby achieving extraction of the sample by vibration; and 3) when the vibration is finished, setting the motor (31) to rotate in the direction opposite to direction A for a second predetermined time, wherein the motor (31) drives the synchronous unidirectional bearing inner ring (41) to rotate relative to the synchronous unidirectional bearing outer ring (42), which causes the elastic connection body (5) to drive the sample tube to rotate, thereby achieving separation of the sample from the extract in the sample tube.

6. The method of claim 5, further comprising: adjusting the first predetermined time and the second predetermined time; and repeating step 2) and step 3) one or more times to achieve separation of the sample from the extract in the sample tube.

7. The method of claim 5, further comprising: placing a plurality of sample tubes symmetrically on the sample tray.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of an oscillation coupling centrifuge in accordance with the present invention, which includes a base 1, a synchronous fixed ring 2, a motor 31, an eccentric shaft 32, a synchronous unidirectional bearing inner ring 41, a synchronous unidirectional bearing outer ring 42, an eccentric unidirectional bearing inner ring 61, an eccentric unidirectional bearing outer ring 62, a sample tray 7, sample tubes 8, samples 81, extracts 82, and an eccentric sleeve 9.

(2) FIG. 2 is a schematic rotation equivalent diagram of the oscillation coupling centrifugal device along direction A, which includes a base 1, a synchronous fixed ring 2, a motor 31, an eccentric shaft 32, an elastic connection body 5, an equivalent eccentric coupling bearing 63, a sample tray 7, sample tubes 8, samples 81, extracts 82, and an eccentric sleeve 9.

(3) FIG. 3 is a schematic rotation equivalent diagram of the oscillation coupling centrifugal device along a direction opposite to direction A, which includes a base 1, a synchronous fixed ring 2, a motor 31, an equivalent shaft coupling body 33, an equivalent synchronous coupling bearings 43, a sample tray 7, sample tubes 8, samples 81, extracts 82, and an eccentric sleeve 9.

DETAILED DESCRIPTION OF IMPLEMENTATIONS

Implementation Example

(4) Chicken samples each weighted 2.00.05 g (accurate to 0.01 g) is placed in the 50 mL centrifuge tube, and are respectively added with appropriate amounts of Amantadine, D15-amantadine, Rimantadine, D4-rosin ethylamine, Chlorpheniramine, D4-chlorobenzene standard working solution, mixed, and let stand for 30 min (using oscillation coupling centrifugation method, directly placing the samples into the 50 mL centrifuge tubes in the outer tube and introducing the standard working solution). Blank samples and samples oscillatory coupling added with 20 g/L of above described chemicals are respectively prepared in parallel. Both blank samples and the samples added with the chemicals are treated using the following two methods. The samples are then analyzed using machines specified in the national standards for food safety animal-derived food Amantadine and Rimantadine residues Determination of Liquid ChromatographyTandem Mass Spectrometry.

(5) (1) Manual treatment method: adding 20 mL of 1% acetic acid acetonitrile solution, whirlpool oscillation for 3 min, adding 2 g of anhydrous magnesium sulfate, vortex for 30 s, centrifuge at 4000 r/min for 5 min. Take 1 mL of the supernatant, add 50 mg of PSA, vortex for 30 s, and centrifuge at 4000 r/min for 3 min. The resulting supernatant was filtered with a 0.22 m filter and measured with LC-MS/MS.

(6) (2) Automatic treatment method: add 2 g of anhydrous magnesium sulfate and 20 mL of 1% acetic acid acetonitrile into the 50 mL sample tube in the centrifuge tube, mix; add 150 mg of PSA into the inner tube, the inner tube inserted into the outer tube, then placed them in the centrifuge. Program 1 setting: clockwise rotation to achieve 8-shaped oscillation for 2 min, and then counterclockwise rotation to centrifuge at 5000 rpm for 3 min. Program 2 setting: clockwise rotation to achieve 8-shaped oscillation for 1 min, and then counterclockwise rotation to centrifuge at 500 rpm for 2 min. Run the two programs. After completion, the resulting supernatant was filtered with a 0.22 m filter and measured with LC-MS/MS.

(7) TABLE-US-00001 TABLE 1 Results of Amantadine in chicken obtained by different sample preparation methods External standard method Internal standard method (n = 3) (n = 3) Order Treatment Matrix Recovery Matrix Recovery No. Chemical Method Effect Rate RSD % Effect Rate RSD % 1 Amantadine Manual 2.59 95% 10 1.08 113% 3.1 2 Automatic 2.4 96% 5.4 0.94 106% 2.3 3 Comparison Manual/ 1.07 0.98 1.85 1.14 1.06 1.34 Result Automatic 4 Amantadine Manual 1.36 75% 8 1.04 99% 3.5 5 Automatic 1.1 96% 4.1 1.06 103% 1.9 6 Comparison Manual/ 1.23 0.78 1.95 0.98 0.96 1.84 Result Automatic

(8) From the above table we can see that there is no significant difference in the matrix effect between the two methods for Amantadine; based on the external standard method, the absolute recovery rate by the oscillation coupling centrifugation method is basically the same as that of the manual treatment method, both being above 95%. Based on the internal standard method, the automatic method and manual treatment method can obtain relatively good recovery rates and accurate results. For Amantadine, there is no significant difference in the matrix effects between the two methods. Based on the external standard method, the difference in absolute recovery rates between the manual treatment and the oscillation coupling centrifugation method is not significant, both being above 75%, whereas the internal standard method can obtain relatively better recovery rates and more accurate results. According to the isotope internal standard method adopted in the draft version of the national standard for food safety titled Determination of Amantadine residues in animal food by liquid chromatographytandem mass spectrometry, the present experiments can produce similar results using the disclosed sample oscillation coupling centrifugal treatment method and manual treatment method.