Domain: Healthcare — Pharmaceutical Chemistry
Target concept: Identification of Levofloxacin Hydrochloride by Ultraviolet Fluorescence Method

Video generation prompt: Place the levofloxacin hydrochloride reference solution and the test solution in quartz cuvettes. Turn on the ultraviolet lamp at the specified wavelength. Compare the fluorescence responses of the reference solution and the test solution under identical conditions. Clearly demonstrate each step, including solution preparation, cuvette placement, ultraviolet irradiation, and result comparison.

Evaluation guide:
(i) Target concept: Identity confirmation via matched fluorescence response under controlled UV excitation.
Minimum mechanism: Levofloxacin hydrochloride must be present in both solutions at sufficient concentration to emit detectable fluorescence; quartz cuvettes must transmit UV light; UV lamp must emit at appropriate wavelength (e.g., 280 nm) to excite the fluorophore; observer must compare responses concurrently under identical optical conditions.
(ii)Storyline: [Frame 0–2] Two labeled quartz cuvettes enter static view, side-by-side, each filled with clear liquid. [Frame 3–4] UV lamp activates: visible light emission begins, illuminating both cuvettes uniformly. [Frame 5–8] Simultaneous, spatially congruent fluorescence glow appears inside both cuvettes: same brightness, same fill pattern, no delay difference. [Frame 9] Lamp remains on; glow persists identically; fixed viewpoint ensures no spatial ambiguity. Visibility constraint: Entire cuvette interiors must remain fully visible and unoccluded throughout; no angle obscures meniscus or emission zone.

Manual:
Experimental Procedure
1. Place levofloxacin hydrochloride reference solution and test solution into separate quartz cuvettes.
2. Position both cuvettes side-by-side under a working ultraviolet lamp set to specified wavelength.
3. Activate UV lamp and observe fluorescence emission from both solutions simultaneously.
Observation of Experimental Phenomena
Both solutions emit visible fluorescence with identical intensity, uniformity, and spatial distribution — confirming identity.
Summary of Experimental Principles
Levofloxacin hydrochloride exhibits characteristic fluorescence under UV irradiation; identical fluorescence response between reference and test solutions confirms chemical identity per pharmacopeial identification method.

Prompt Grounding rubric:
level_1: Neither the two quartz cuvettes nor the reference/test solutions appear on screen, no UV lamp is visible anywhere, and no comparison of the two solutions is depicted. The scene does not resemble this identification test at all.
level_2: One cuvette and one solution (reference or test) appear, but the two are not shown together the way the procedure calls for, the UV lamp is visible but never switched on, and there is no depiction of comparing the two solutions.
level_3: Both quartz cuvettes appear together in the same shot with a solution visible in each, the UV lamp is clearly switched on (emitting light or showing an active indicator), and the framing makes clear the two cuvettes are meant to be compared; neither cuvette's identity (reference vs. test) is confused with the other.
level_4: Everything a 3 needs is present, and further: each cuvette is clearly and legibly marked as reference or test; the UV lamp's light visibly reaches both cuvettes at the same time; and the camera framing (both cuvettes held together in view, with no cut to just one) makes the comparison between them unmistakable.
level_5: Everything a 4 needs is present, and further: both cuvettes stay in place and fully visible for the entire clip; the reference/test labels stay legible and unobstructed throughout; the lamp stays on continuously without flicker; and there is no cut, zoom, or repositioning that breaks the single fixed shot in which both cuvettes are held together for comparison.

Scientific and Causal Correctness rubric:
level_1: Neither solution shows any fluorescence under the UV lamp, both solutions look identical in showing no response at all (nothing to compare), fluorescence is visible before the lamp is even turned on, or both cuvettes glow even though something about the setup (e.g., a blank solvent) shouldn't fluoresce.
level_2: Only one of the two solutions fluoresces and it doesn't match the other (e.g., the test solution glows while the reference stays dark, or vice versa, with no correspondence between them); or fluorescence appears to come from outside the cuvettes rather than from the solutions themselves; or the emitted color is implausible for this UV excitation (e.g., a saturated red glow).
level_3: Both solutions fluoresce once the lamp is on, staying confined within their cuvettes, but the clip doesn't clearly show whether their brightness or pattern actually match: for example the two glows look roughly similar, but the comparison isn't crisp enough to call it a clean match.
level_4: Both the reference and the test solutions fluoresce with visibly matching brightness and the same even, uniform look inside their cuvettes (no visible difference between them), and both light up only while the lamp is on, with no extra glow or reflection elsewhere that could be mistaken for fluorescence.
level_5: Everything a 4 needs is present, and further: both solutions start and stop glowing at the same moment relative to the lamp switching on and off; neither shows a lingering afterglow once the lamp is off; neither flickers or drifts in brightness while lit; and the glow fills each cuvette evenly with no pooling, streaking, or brighter edges that would suggest the two solutions aren't behaving the same way.

Spatiotemporal Consistency rubric:
level_1: The cuvettes jump to a different spot between frames, the lamp appears or disappears with no transition, the solution levels change in a jump rather than smoothly, the lighting suddenly shifts for no reason connected to the lamp turning on, or the shot cuts or jumps mid-sequence.
level_2: One cuvette rotates or slides sideways between frames, a label's position shifts relative to its cuvette across frames, the lamp switches on with a visible flicker or a slow ramp-up that doesn't match how a real UV lamp behaves, or the shadows cast by the cuvettes shift in a way that doesn't track a single fixed light source.
level_3: Both cuvettes stay fixed in position and orientation, the lamp stays in place and consistently lit once on, nothing unexpectedly enters or leaves the frame, the overall lighting stays steady apart from the fluorescence itself, and neither cuvette shows any warping or the liquid surface distorting across frames.
level_4: Everything a 3 needs is present, and further: the two cuvettes keep the same side-by-side spacing, height, and orientation relative to each other throughout; there's no camera drift or shake suggesting the camera itself is moving; and the glow inside each cuvette keeps a consistent shape and boundary relative to the cuvette walls across every frame.
level_5: Everything a 4 needs is present, and further: the clip shows no repeated or dropped frames and no change in playback speed; any hand motion (e.g., placing the cuvettes) is smooth and physically natural; nothing ever blocks the view into either cuvette's interior; and the fluorescence in both cuvettes turns on and off together, staying visually matched in timing throughout every frame it's active.