Device for high spatial resolution chemical analysis of a sample and method of high spatial resolution chemical analysis
A system and method for analyzing a chemical composition of a specimen are described. The system can include at least one pin; a sampling device configured to contact a liquid with a specimen on the at least one pin to form a testing solution; and a stepper mechanism configured to move the at least one pin and the sampling device relative to one another. The system can also include an analytical instrument for determining a chemical composition of the specimen from the testing solution. In particular, the systems and methods described herein enable chemical analysis of specimens, such as tissue, to be evaluated in a manner that the spatial-resolution is limited by the size of the pins used to obtain tissue samples, not the size of the sampling device used to solubilize the samples coupled to the pins.
1. A system for analyzing a chemical composition of a specimen, comprising:
a plurality of pins closed to liquid flow and each having a tip for contacting a sample and retaining sample over the pin tip, the pins being spaced apart such that sample on one pin does not contact sample on any adjacent pin;
a sampling device configured to contact a liquid with a specimen on the tip of at least one pin to form a testing solution; wherein
said sampling device comprises a capillary tube defining an outer perimeter of a capillary in fluid communication with an external orifice of said sampling device, said external orifice for forming a meniscus with a liquid in said capillary tube; the tube having a first position where the orifice is distanced from the pin tip such that liquid does not contact the pin tip; and
a mechanism for moving said at least one pin and said sampling device relative to one another to a second position such that sample on a single pin tip contacts the meniscus and sample on the pin tip is transferred into the liquid to create a testing solution.
2. The system according to claim 1 , further comprising:
an analytical instrument for determining a chemical composition of said specimen from said testing solution.
3. The system according to claim 2 , wherein said sampling device dispenses said testing solution into said analytical instrument.
4. The system according to claim 3 , wherein said analytical instrument is a mass spectrometer, an ionization source, a separation method, or a combination thereof.
5. The system according to claim 1 , wherein said sampling device further comprises an inner capillary tube disposed within said capillary tube, said inner capillary tube defining an outer perimeter of an inner capillary, wherein said capillary and said inner capillary are in fluid communication at a distal end of said sampling device.
6. The system according to claim 1 , wherein said moving mechanism is configured to move said at least one pin and said sampling device such that said sampling device sequentially and individually dissolves samples on more than one pin.
7. The system according to claim 1 , wherein a plurality of pins are provided in an array.
8. The system according to claim 7 , wherein said array of pins comprises an array of regularly spaced pins.
9. The system according to claim 8 , wherein said array of pins has a regular center-to-center spacing in a direction, and wherein a maximum dimension across a distal end of said sampling device in said direction is more than twice said regular spacing in said direction.
10. The system according to claim 1 , wherein a tip of said at least one pin comprises at least one of a solid phase microextraction (SPME) coating, taper, a prong and a punch.