diff --git a/metbit/dev/take_intensity.py b/metbit/dev/take_intensity.py
index dea5819..17e5ae0 100644
--- a/metbit/dev/take_intensity.py
+++ b/metbit/dev/take_intensity.py
@@ -239,8 +239,9 @@ def export_x_positions(n_clicks, stored_peaks):
 
             x_positions = [p['x'] for p in stored_peaks]
             df = pd.DataFrame(x_positions, columns=["X Positions"])
-            peak_list = df['X Positions'].to_list()
-            export_intensity = spectra.iloc[:, peak_list]
+            #convert str list
+            x_positions = [str(i) for i in x_positions]
+            export_intensity = spectra.loc[:, x_positions]
             csv_string = export_intensity.to_csv(index=False)
 
 
diff --git a/setup.py b/setup.py
index 4240a88..dceffe4 100644
--- a/setup.py
+++ b/setup.py
@@ -12,13 +12,13 @@
 setup(
   name = 'metbit',      
   packages = ['metbit'], 
-  version = '6.7.1',  
+  version = '6.7.2',  
   license='MIT', 
   description = 'Metabolomics data analysis and visualization tools.',
   author = 'aeiwz',                 
   author_email = 'theerayut_aeiw_123@hotmail.com',   
   url = 'https://github.com/aeiwz/metbit.git',  
-  download_url = 'https://github.com/aeiwz/metbit/archive/refs/tags/V6.7.1.tar.gz',  
+  download_url = 'https://github.com/aeiwz/metbit/archive/refs/tags/V6.7.2.tar.gz',  
   keywords = ['Omics', 'Multivariate analysis', 'Visualization', 'Data Analysis', 'Metabolomics', 'Chemometrics'],
   install_requires=[            
           'scikit-learn',