Home
Back
pH Calculation Formula:
| From: | To: |
The pH calculation converts hydrogen ion concentration ([H⁺]) to pH using the logarithmic formula pH = -log₁₀([H⁺]). This is essential in blood gas analysis to determine the acidity or alkalinity of blood.
The calculator uses the pH formula:
Where:
Explanation: The pH scale is logarithmic, meaning each whole pH value below 7 is ten times more acidic than the next higher value.
Details: Accurate pH measurement is crucial for assessing acid-base balance in the body, diagnosing respiratory and metabolic disorders, and guiding appropriate medical treatment.
Tips: Enter hydrogen ion concentration in nmol/L. The value must be greater than 0. The calculator will automatically convert to mol/L and compute the pH value.
Q1: What is the normal pH range for blood?
A: The normal arterial blood pH range is 7.35-7.45. Values below 7.35 indicate acidosis, while values above 7.45 indicate alkalosis.
Q2: Why use nmol/L instead of mol/L for hydrogen ion concentration?
A: nmol/L (nanomoles per liter) is commonly used in clinical practice because hydrogen ion concentrations in blood are very small, typically ranging from 35-45 nmol/L for normal pH.
Q3: How does temperature affect pH measurement?
A: pH measurements are temperature-dependent. Blood gas analyzers typically measure pH at 37°C and may apply temperature correction factors if needed.
Q4: What are common sources of error in pH measurement?
A: Common errors include improper sample handling, air bubbles in the sample, delayed analysis, and improper calibration of the blood gas analyzer.
Q5: How is pH related to pCO₂ and bicarbonate in blood gas analysis?
A: pH, pCO₂, and bicarbonate are interrelated through the Henderson-Hasselbalch equation, which describes the acid-base balance in the blood and helps diagnose respiratory vs. metabolic disorders.