Domain: Healthcare — Nutrition and Food Hygiene
Target concept: Determination of Diethyl Phthalate

Video generation prompt: A test tube containing 10 mL of food packaging extract containing a plasticizer (diethyl phthalate) was treated with resorcinol-sulfuric acid solution and boiled for 3 minutes.

Evaluation guide:
(i) Target concept: Chromogenic detection of phthalate esters via condensation reaction under acidic thermal conditions.
Minimum mechanism: Resorcinol must contact phthalate ester in concentrated sulfuric acid medium and undergo cyclization/dehydration upon heating to yield a conjugated quinoidal dye (red-purple).
(ii)Storyline: [Frame 0–2] Static shot of upright test tube containing ~10 mL pale liquid (extract); [Frame 3–4] Resorcinol-sulfuric acid solution dispensed into tube (visible liquid stream); [Frame 5–7] Boiling initiates (bubbles rise, steam emerges from mouth); [Frame 8–10] Red-purple color uniformly fills liquid column, persisting through final frame. Perspective: Fixed frontal view, centered on test tube; no hand/tool intrusion; all critical events occur within tube volume and its immediate aperture; no off-screen actions implied.

Manual:
Experimental Procedure
1. Place 10 mL food packaging extract (diethyl phthalate-containing) in a clean test tube.
2. Add resorcinol-sulfuric acid solution to the test tube.
3. Boil the mixture for 3 minutes.
Observation of Experimental Phenomena
A distinct red-purple color develops in the solution during boiling.
Summary of Experimental Principles
Resorcinol-sulfuric acid reacts specifically with phthalate esters under heat to form a red-purple chromogen — used for qualitative detection of plasticizers like diethyl phthalate in food contact materials.

Prompt Grounding rubric:
level_1: No test tube is visible; or no resorcinol-sulfuric acid reagent is shown being added; or no boiling is depicted; or the food packaging extract is missing; none of the three core elements (test tube, extract, reagent) appear together in the scene.
level_2: At least one core element appears (e.g., the test tube), but the reagent is missing or is clearly mislabeled as something else (e.g., shown as plain water or a different acid); the extract's liquid level is not close to filling about half of a standard test tube; boiling is missing or replaced by simple stirring or shaking; there is no visible order of reagent addition followed by heating.
level_3: A clear cylindrical test tube holds a liquid column reaching roughly the mid-height expected for a 10 mL sample; the liquid is identifiable, by label or context, as a food-packaging extract containing diethyl phthalate; the resorcinol-sulfuric acid reagent is visibly added to the tube; vigorous bubbling and rising steam (boiling) occur only after the reagent has been added, in that order.
level_4: Everything at the 3-point level holds, plus: the test tube stays upright and in place throughout; the reagent container or dropper is labeled or otherwise identifiable as resorcinol-sulfuric acid; the extract's container or label identifies it as food packaging extract; boiling continues for a sustained stretch (visible as more than one distinct burst of bubbling and steam, not a single brief puff), with no cut in the camera view or sudden jump in the action.
level_5: Everything at the 4-point level holds, plus: the reagent is delivered with a dropper or pipette rather than poured from an open beaker; steam rises only from the mouth of the test tube and nowhere else in the frame; no extra containers, hands, or tools enter the shot beyond what the procedure requires; the camera keeps a fixed frontal framing on the tube for the entire clip; any text labels present are readable, even if not typeset with perfect precision.

Scientific and Causal Correctness rubric:
level_1: The liquid in the test tube shows no color change at all after boiling: it stays the same pale color it started as; or cloudiness or a solid precipitate appears instead of a color change; none of this matches the expected resorcinol-sulfuric acid reaction with the phthalate ester extract.
level_2: A color change happens, but the wrong color appears: for example the liquid turns blue, green, or plain yellow rather than red-purple; or the color appears before the reagent is added or before boiling starts; or cloudy turbidity forms without any boiling taking place.
level_3: A distinct red-purple color develops in the test tube's liquid during or right after boiling; the color fills the entire liquid column evenly; no unrelated phenomenon (charring, a separate liquid layer, a solid precipitate) dominates the scene; the color only shows up once boiling has begun and stays visible for the rest of the clip.
level_4: Everything at the 3-point level holds, plus: the red-purple color is strong and clearly different from both the colorless or pale-yellow starting extract and the colorless reagent; there is no separate brownish discoloration at the liquid's surface or along the tube wall; the color appears while boiling is at its most vigorous, near a burst of bubbling, rather than well before or long after it.
level_5: Everything at the 4-point level holds, plus: the red-purple color is even from the bottom of the tube to the liquid surface, with no streaks, layers, or gradient; no brown or black charring and no unrelated gas bubbles appear alongside the boiling; the red-purple color stays steady (it does not fade or drift toward blue or orange) for the remainder of the video.

Spatiotemporal Consistency rubric:
level_1: The test tube instantly jumps to a different position or angle between shots; the liquid level inside jumps up or down with no visible cause; boiling appears and then vanishes with no transition; the scene's lighting switches abruptly, for example from bright to dim, partway through; the tube itself bends or twists unnaturally.
level_2: The test tube visibly shifts position or tilts by roughly a quarter of its width or more between one frame and the next; steam appears or disappears suddenly with no fade-in or fade-out; the reagent liquid appears to materialize in mid-air rather than being poured or dropped in; the shadow cast by the tube flips to the opposite side with no change in where the light is coming from.
level_3: The test tube shows only slight, barely noticeable jitter in its position; steam rises and dissipates without any sudden on/off flicker; the overall brightness in the shot stays visually steady rather than flashing or pulsing; the tube stays a single unbroken cylinder throughout, with no teleporting and no lighting that suddenly reverses direction.
level_4: Everything at the 3-point level holds, plus: the test tube stays rigid and keeps the same cylindrical shape and camera-relative angle throughout, with no bending, warping, or perspective skew; steam rises along a single upward path without drifting sideways or breaking into disconnected puffs; the liquid's surface keeps a consistent, slightly curved meniscus the whole time; nothing blocks the view of the tube and the focus does not suddenly shift.
level_5: Everything at the 4-point level holds, plus: the boiling bubbles rise smoothly and grow gradually in size rather than popping in and out inconsistently; the steam plume widens gradually as it disperses, rather than jumping in size; there is no ghosting, duplicated frame, or motion blur that hides the tube's outline; the tube's position and centering in the frame, along with any visible reagent-bottle placement nearby, stay the same relative to each other throughout the video.