Abstract: A long-path gas absorption cell reflective optical system, which includes a first reflector (1) and a second reflector (2), the first reflector (1) and the second reflector (2) are set opposite and spaced apart, with the second reflector (2) having an optical input port (3) and an optical output port (4). The first reflector (1), the second reflector (2), the optical input port (3), and the optical output port (4) together constitute a multiple reflection optical system; a collimated light beam enters through the optical input port (3) and reflects between the first reflector (1) and the second reflector (2), finally exiting through the optical output port (4). This achieves a longer light path for the collimated light beam within a limited space, allowing for more reflections; the system has a simple structure, relatively simple optical adjustment, is easy to operate, and has stable performance, making it widely applicable in various detection environments.

Abstract: A long-path gas absorption cell reflective optical system, which includes a first reflector (1) and a second reflector (2), the first reflector (1) and the second reflector (2) are set opposite and spaced apart, with the second reflector (2) having an optical input port (3) and an optical output port (4). The first reflector (1), the second reflector (2), the optical input port (3), and the optical output port (4) together constitute a multiple reflection optical system; a collimated light beam enters through the optical input port (3) and reflects between the first reflector (1) and the second reflector (2), finally exiting through the optical output port (4). This achieves a longer light path for the collimated light beam within a limited space, allowing for more reflections; the system has a simple structure, relatively simple optical adjustment, is easy to operate, and has stable performance, making it widely applicable in various detection environments.

Abstract: A method of use of a cysteine labeling system includes: providing a 2-cyano benzothial core with a covalently-linked biomolecule X in a reaction environment; and reacting the 2-cyano benzothial core to an N-terminal cystenine.