Domain: Engineering — Food and Bioprocess Engineering
Target concept: Lutein Determination (Ethanol Extraction - Fluorescence Method)

Video generation prompt: Take 3 grams of spinach leaf homogenate and place it in a beaker. Add 10 mL of anhydrous ethanol for extraction. After filtration, transfer the filtrate into a quartz cuvette and observe its color under blue-light excitation at 445 nm.

Evaluation guide:
(i) Target concept: Detecting lutein extracted from spinach requires ethanol extraction, filtration to remove solids, and observing the filtrate's response to blue-light excitation (445 nm) in a cuvette.
Minimum mechanism: Lutein, a yellow-orange xanthophyll pigment, must be dissolved out of the spinach tissue by ethanol and separated from solid plant matter by filtration before its response to 445 nm light can be observed; because lutein and other carotenoids fluoresce only weakly under blue-light excitation, any resulting fluorescence should appear as a faint, dim glow rather than repeating the strong yellow-orange the filtrate shows under ordinary room light -- any break in the extraction-filtration chain (e.g., observing the raw homogenate instead of a clear filtrate) invalidates the phenomenon.
(ii)Storyline: [Frame 0-2] Spinach homogenate (green-brown, opaque, particulate) is placed into a beaker -> [Frame 3-4] Anhydrous ethanol (colorless liquid) is added, forming a suspension -> [Frame 5-6] Filtration occurs (implied by a clear yellow-orange liquid appearing in the collection vessel or beaker bottom) -> [Frame 7] The clear filtrate is transferred into a quartz cuvette (rectangular, clear, no bubbles) -> [Frame 8-9] A handheld 445 nm blue-light lamp illuminates the cuvette -> [Frame 10] The cuvette's contents show at most a faint glow under the lamp, distinctly dimmer than the filtrate's own yellow-orange color in room light; no glow appears from the surroundings, and any glow disappears as soon as the lamp is switched off. Perspective: Fixed overhead/frontal view; all actions fully visible; no occlusion of critical interfaces (beaker rim, filter junction, cuvette meniscus, lamp-cuvette contact zone).

Manual:
Experimental Procedure
1. Place 3 g spinach leaf homogenate into a beaker.
2. Add 10 mL anhydrous ethanol.
3. Filter mixture; collect clear filtrate.
4. Transfer filtrate into a quartz cuvette.
5. Excite under 445 nm blue light and observe.
Observation of Experimental Phenomena
Filtrate is yellow-orange in ambient light; under 445 nm blue-light excitation, it shows at most a faint, dim fluorescence glow confined to the cuvette -- much weaker than its ordinary yellow-orange appearance in room light.
Summary of Experimental Principles
Lutein, a xanthophyll carotenoid in spinach, is extracted by anhydrous ethanol due to its lipid solubility, and purified by filtration. Its yellow-orange color in ordinary light comes from strong absorption of blue light around 445 nm. Like other carotenoids, lutein has a very low fluorescence quantum yield, so any fluorescence it emits (in the roughly 475-510 nm, blue-green region) is faint rather than bright. A quartz cuvette is used here per standard protocol; since 445 nm is visible (not UV) light, ordinary glass would also transmit it adequately.

Prompt Grounding rubric:
level_1: No spinach leaf homogenate is shown; no beaker is present; no ethanol container or liquid appears; no cuvette is present; no blue-light lamp or excitation step is depicted.
level_2: At least one of the required objects appears (spinach homogenate, beaker, or cuvette), but the core actions are missing -- homogenate is never placed in a beaker, ethanol is never added, filtration is never implied, the filtrate is never transferred to a cuvette, and the lamp/excitation scene never occurs.
level_3: All three core objects are present -- a green-brown spinach homogenate, a beaker, and a clear rectangular cuvette; a colorless liquid consistent with ethanol is added to the beaker; the homogenate is placed into the beaker; the liquid is added to the beaker; a clear (or clearer) filtrate is transferred into the cuvette; a lamp-excitation scene occurs -- but at least one action happens out of order (e.g., the cuvette appears full before any filtration step is implied).
level_4: All of score 3, and every object is clearly identifiable by type: opaque green-brown spinach homogenate, a cylindrical transparent beaker, a colorless liquid (ethanol) poured into the beaker, a clear rectangular cuvette with flat optical faces, and a handheld lamp emitting a distinctly violet-blue light consistent with 445 nm; the five steps -- homogenate into beaker, ethanol added, filtration implied by a clearing/color change of the liquid, filtrate transferred to the cuvette, cuvette placed under the lamp and observed -- occur in this order with no step skipped or reordered.
level_5: All of score 4, and the homogenate is unambiguously spinach-derived (visible leaf fragments or a green tint typical of leafy greens); the liquid added is visually distinguishable from water (no separate water layer or cloudiness, consistent with a pure solvent); the cuvette is a clean, clear rectangular vessel with sharp optical faces and no visible cracks, scratches, or bubbles (the video need not prove the material is quartz specifically, since quartz and glass are visually indistinguishable on camera); the lamp's light is confined to illuminating the cuvette and its contents without a bright glow washing out the beaker or background; no extraneous labels, tools, or on-screen text/overlays appear.

Scientific and Causal Correctness rubric:
level_1: No response is visible under the lamp; the cuvette's contents look colorless, black, or unchanged in hue; the liquid placed in the cuvette is itself turbid or green rather than a clear yellow-orange filtrate; or a clearly wrong hue appears (e.g., a strong red or blue glow, inconsistent with any carotenoid).
level_2: A glow appears but the details are off: it is as bright and saturated as the filtrate's own daylight color rather than distinctly fainter, it appears even from unfiltered or turbid liquid, or its color is clearly wrong (strongly reddish or bluish rather than any green or yellow tone).
level_3: The filtrate is clear and yellow-orange in ordinary light; when the lamp illuminates it, the cuvette's contents show a modest change in appearance -- a subtle glow or hue shift that is visibly dimmer and less saturated than the filtrate's own daylight color. Minor inconsistencies are tolerated, such as the glow being a bit brighter than expected or lingering slightly after the lamp is removed.
level_4: All of score 3, and the glow is confined to the cuvette's contents only (not visible on the beaker, bench, or background), disappears as soon as the lamp is switched off, and its hue leans toward green or blue-green rather than repeating the same yellow-orange seen in daylight.
level_5: All of score 4, and the faintness of the glow looks consistent across the visible liquid (not brighter only where the lamp beam directly hits one spot), and the filtrate's daylight yellow-orange color looks the same before and after the lamp exposure, with no visible fading or bleaching.

Spatiotemporal Consistency rubric:
level_1: The homogenate appears inside the beaker with no placement action shown; the cuvette appears already full without any transfer being shown; the lamp appears switched on while the cuvette is empty; the room's ambient light abruptly vanishes or changes color mid-sequence; or the beaker or cuvette shows a broken or misaligned structure (e.g., a corner of the cuvette warps, or the beaker appears split).
level_2: Two or more major discontinuities occur, such as: a hard cut from homogenate-in-beaker directly to a full cuvette with no visible transfer, then another cut directly to the glowing cuvette; no visible motion during the ethanol pour or the filtration step; the cuvette's orientation changes abruptly between shots; or the shadow cast by the beaker or cuvette swaps sides between shots with no camera movement to explain it.
level_3: The beaker and cuvette keep consistent positions relative to each other and the tabletop throughout; the handheld lamp stays in roughly the same position relative to the cuvette once it appears; motion during placement, pouring, and transfer is continuous with no jump cuts. Small flaws are tolerable, such as the cuvette being briefly hidden by a hand during the transfer, or a short flicker in the lamp's beam.
level_4: All of score 3, and every motion is smooth and physically plausible: the homogenate is visibly scooped or poured into the beaker, the ethanol pours as a continuous stream, filtration is shown or clearly implied in one coherent shot (liquid passing through a filter, or a clear filtrate appearing at the bottom of a vessel), the filtrate is poured or pipetted steadily into the cuvette, and the cuvette sits upright and still while the lamp illuminates it; the lamp's light and the shadows it casts on the beaker/cuvette shift only if the lamp or the objects visibly move, with no unexplained jump in shadow position or sudden change in the color of the ambient light.
level_5: All of score 4, and the pace of every action looks physically appropriate for its material (the ethanol pours at a liquid-appropriate rate, the homogenate has a paste-like consistency when it contacts the beaker, the filtrate's meniscus forms smoothly in the cuvette); there is no frame stutter, ghosting, or visible camera shake during any step; object edges (beaker rim, cuvette corners, lamp housing) stay sharp and stable across frames; and the relative depth ordering of beaker, cuvette, and lamp stays consistent with no foreground/background swapping.