緩衝液配製計算器 Buffer Preparation Calculator

步驟 1：緩衝系統 (Step 1: Buffer System)

• 中文說明： 從下拉選單選擇欲配製的緩衝系統（如磷酸鹽、Tris、HEPES、檸檬酸等），選單旁會同時顯示該系統的建議 pH 範圍。若選擇檸檬酸，會出現「酸鹼對版本」子選單，可切換「簡化版 (H₃A／Na₃A)」或「嚴謹版 (NaH₂A／Na₂HA)」。接著選擇酸型與鹼型鹽類的實際形態（是否含結晶水），系統會自動帶入對應分子量；若清單中沒有您需要的系統，可選擇「自訂」自行輸入名稱與分子量。

• English Instructions： Choose a buffer system from the dropdown (e.g., Phosphate, Tris, HEPES, Citrate); the recommended pH range appears next to each option. Selecting Citrate reveals a "Salt-pair variant" sub-selector to switch between the simplified (H₃A/Na₃A) and rigorous (NaH₂A/Na₂HA) pairs. Then pick the specific acid- and base-form salts (anhydrous vs. hydrate), and their molecular weights auto-fill. If your system isn't listed, choose "Custom" to enter your own names and molecular weights.

步驟 2：pKa 與溫度校正 (Step 2: pKa & Temperature Correction)

• 中文說明： 參考 pKa（25°C）與溫度係數 (dpKa/dT) 會依所選系統自動帶入常見文獻值，但兩者皆可自行修改以貼近您的資料來源。輸入實際配製溫度後，系統會即時算出「溫度校正後 pKa」。若選擇 Tris，可勾選「使用 Tris 動態溫度係數」，改以文獻分段斜率（0–10／10–20／20–30／30°C 以上）逐段積分計算，較單一線性係數更精確。

• English Instructions： Reference pKa (25°C) and the temperature coefficient (dpKa/dT) auto-fill with common literature values for the selected system, but both remain freely editable. Enter the actual preparation temperature to get a live temperature-corrected pKa. For Tris, check "Dynamic Tris coefficient" to use piecewise-integrated literature slopes (0–10 / 10–20 / 20–30 / above 30°C) instead of a single linear coefficient, for higher accuracy.

步驟 3：離子強度校正 (Step 3: Ionic Strength Correction)

• 中文說明： 勾選「套用離子強度校正」後，系統會以 Davies 方程式（Debye–Hückel 的經驗延伸式）估算離子強度對表觀 pKa 的影響。選擇「自訂」系統時，需輸入酸型電荷 z(HA)，並可選擇性覆寫共軛鹼電荷 z(A⁻)（預設為 zAcid − 1）。也可額外輸入其他鹽類（如 NaCl）的濃度，一併計入離子強度估算。校正後的「有效 pKa」會即時顯示於下方欄位。

• English Instructions： Check "Apply ionic-strength correction" to estimate the effect of ionic strength on the apparent pKa using the Davies equation (an empirical extension of Debye–Hückel). For "Custom" systems, enter the acid-form charge z(HA); you may optionally override the conjugate-base charge z(A⁻) (defaults to zAcid − 1). You can also add the concentration of other dissolved salts (e.g., NaCl) to include in the ionic-strength estimate. The resulting "Effective pKa" updates live in the box below.

步驟 4：目標條件 (Step 4: Target Conditions)

• 中文說明： 輸入目標 pH（0–14）、總濃度（支援 M 或 mM）與配製體積（支援 L 或 mL）。下方會即時顯示 pH 刻度尺，標示目標 pH、有效 pKa 位置及該系統的建議緩衝範圍，方便您在計算前快速確認是否落在有效範圍內。

• English Instructions： Enter the target pH (0–14), total concentration (M or mM), and final volume (L or mL). A live pH scale below shows the target pH, the effective pKa, and the system's recommended buffering range, so you can check at a glance whether your target falls within it before calculating.

步驟 5：計算配方 (Step 5: Calculate Recipe)

• 中文說明： 點擊「計算配方」後，系統會依 Henderson–Hasselbalch 方程式（多質子系統則改用電荷守恆聯立求解）算出兩種鹽類各自應秤取的重量，並列出與「未校正 pKa」比較的差異表。若目標 pH 超出該系統建議範圍，配方仍會產出，但會以紅色標籤與警告文字提醒緩衝能力可能不足。點擊「顯示計算過程」可展開完整推導式，包含溫度校正、離子強度校正與 Henderson–Hasselbalch（或多質子）計算步驟。

• English Instructions： Click "Calculate Recipe" to get the mass of each salt needed, solved via the Henderson–Hasselbalch equation (or a charge-balance solver for polyprotic systems), along with a comparison table against the uncorrected pKa. If the target pH falls outside the system's recommended range, the recipe is still calculated but flagged with a red label and warning that buffering capacity may be insufficient. Click "Show calculation steps" to expand the full derivation, including temperature correction, ionic-strength correction, and the Henderson–Hasselbalch (or polyprotic) calculation.